Uh ? You haven't been around many open source projects. It has nothing to do with money.
You just want it to be so. Reality obviously tells a different story. Otherwise, provide sources for your claim.
Opera Mini does not have a Javascript engine nor does it have a HTML rendering engine. Apple absolutely does not allow 3rd parties to implement Javascript/Rendering engines.
Again, you just want it to be Google's fault. The fact remains : Google cannot use anything but UIWebView, so they are stuck with all its limitations (no Nitro, no background thread rendering, etc...). All browsers on iOS are limited this way.
Opera Mini is not a browser per se. It does not fetch and render HTML on your IOS device. I think you need to read up on how Opera Mini works.