My opinion is that Google/Mozila is pushing HTML5 instead of plugins not because that's what's best for the web, but because exactly this-- it decreases the potential for competition.
If you really want to get a good conspiracy theory going, note that a lot of the main Camino people have worked at Google for many years now (longer than Chrome has existed), and the other main person went to Apple.
The whole reason Camino has been discontinued is that the components that make it easy to reuse Gecko in their competing product were removed from Gecko.
I'd like to see your source for that claim. At first glance it seems that popularity of Camino, both among its developers and its users, has been declining for years.
A big counter-example is Opera Software switching away from their own engine to WebKit/Blink.
Opera has a paid staff of full-time engineers, which makes rewriting a browser on top of a new engine a lot more feasible.
You're right in that if Camino had the developer time it had in its heyday it might have made the jump and survived, but the end of Gecko embedding is what made it impossible for Camino to continue to be maintained indefinitely by one or two people.
In what way does using HTML5 over plugins decrease the potential for competition? If anything it makes for more competition as the need for browser-specific plugins is removed.
