If they want this to be the next Django/Rails/Express/whatever, where a large and enthusiastic community both uses and develops the product then the answer is fairly clear: No, this is not a suitable license.
If their idea is that it's an nominally open source project where all control and most development takes place inside the originating company, and the community mostly just pays license fees then: Sure, it's a great license.
Longer clarification: Django is licensed under BSD, Rails and Express under MIT. Why? Because these licenses allow me to use these frameworks for my own webapps, without making the entire client/server code base available. I can toss together a Rails-based contacts manager, or a Django-based todo list app, and let people sign up, and even charge a monthly fee, and NOT have to give the code to the entire app out.
In short, as long as Meteor is under the GPL, I can use the framework for free, but I cannot let anyone use a webapp I create with it without giving away all the source code. Which means that I'm very unlikely to actually install and try Meteor on my next project. My choices are basically "ignore Meteor" and "pay a license fee to the devs". Meteor is awesome, and probably well worth the license fee (whatever it might be), but it's fairly obvious that this is a huge limitation on the frameworks potential for adoption.
(It's worth noting that both Django and Rails were actually developed for a project, and then released under permissive licenses, because the framework wasn't the product, and the dev teams didn't need to try and monetize it. Meteor is the product, and the dev team does need to monetize it. And, again, Meteor looks awesome! So I can fully understand why they chose GPL, and I fully support that choice! But it is worth noting the consequences of that.)
In the twenty-five or so years of the free-software movement, we've built the Internet and the World-Wide Web; made the Encyclopedia Britannica obsolete by producing something dramatically better; built history's most portable operating system, which now runs everything from most smartphones to most supercomputers, with contributions from hundreds of companies, including its biggest competitors, IBM and Microsoft.
But even after twenty-five years, there are still people who think they have to make a code base proprietary to make money on it.
I'm horrified.
What do you think will happen if you toss together a contacts manager or to-do list app and charge a monthly fee, and give out all the code, just as the Meteor devs have given out all their code to you? Maybe some of your users will decide to run the app on their own server and stop paying you. Or try to compete with you. But probably most of them will want to use the site operated by the app's primary developer. And all of your would-be competitors are just free R&D increasing the value of your site.
What's so terrible about making web apps that are free software?
You seem confused. :) There's nothing at all wrong with making webapps that are, themselves, open source. It's actually a good thing!
But open source frameworks and languages that try and give developers the maximum freedom to make whatever they want see much higher adoption, uptake, mindshare, marketshare, engagement, developer excitement, community participation, user-submitted bug fixes, etc., etc., etc. than ones which don't.
Start listing popular frameworks - how many of those frameworks are GPL?
Off the top of my head, I would name: Sinatra, Rails, Django, Flask, Backbone, Batman, Knockout, Tir, CakePHP, Symfony, Spine, CherryPy, web.py, Pyramid, Zend, and Brubeck. Of those, every single one except Brubeck is licensed with BSD, MIT, or some variant - and Brubeckmight be too; I couldn't find license info.
There's nothing terrible about making web app that are free software...but the plain truth is, people don't make web apps that are free software with frameworks that require that. They go pick one of the popular frameworks, which all have permissive licenses. You can be horrified if you want. :)
Nothing. I've made several and made money on them. (Wikitravel, StatusNet). There are others who have done so, too -- WordPress.com being the classic. Probably the biggest place we're seeing this right now is in IaaS and PaaS efforts -- OpenStack, Nodester, CloudStack, OpenShift, CloudFoundry. Open Source all the way.
If they want this to be the next Django/Rails/Express/whatever, where a large and enthusiastic community both uses and develops the product then the answer is fairly clear: No, this is not a suitable license.
If their idea is that it's an nominally open source project where all control and most development takes place inside the originating company, and the community mostly just pays license fees then: Sure, it's a great license.
Longer clarification: Django is licensed under BSD, Rails and Express under MIT. Why? Because these licenses allow me to use these frameworks for my own webapps, without making the entire client/server code base available. I can toss together a Rails-based contacts manager, or a Django-based todo list app, and let people sign up, and even charge a monthly fee, and NOT have to give the code to the entire app out.
Someone else linked to Sencha's discussion of the GPL and JS webapps, and it's highly relevant: http://www.sencha.com/legal/open-source-faq/
In short, as long as Meteor is under the GPL, I can use the framework for free, but I cannot let anyone use a webapp I create with it without giving away all the source code. Which means that I'm very unlikely to actually install and try Meteor on my next project. My choices are basically "ignore Meteor" and "pay a license fee to the devs". Meteor is awesome, and probably well worth the license fee (whatever it might be), but it's fairly obvious that this is a huge limitation on the frameworks potential for adoption.
(It's worth noting that both Django and Rails were actually developed for a project, and then released under permissive licenses, because the framework wasn't the product, and the dev teams didn't need to try and monetize it. Meteor is the product, and the dev team does need to monetize it. And, again, Meteor looks awesome! So I can fully understand why they chose GPL, and I fully support that choice! But it is worth noting the consequences of that.)