You often do though. For example if you want to do open source development on JS projects, this means that you might have to learn many different build systems.

Yeah, where “often” is defined as “this one example that I just conjured up”.

Yep, you're right. It's anecdotal evidence, of which you have 2 data points on this thread. We're extrapolating here from what we've seen, for sure. If you have better data, please do share.

I know I'm right. Thanks.

Aw, I was hoping you'd actually follow up with some meaningful data. :(

Same

Our anecdotal evidence trumps your no evidence. ;)