Of course developers wanted this. They wanted to push all the complexity into the browser so they didn't have to worry about it themselves. Google was happy to provide this because it meant that they could be the only ones that could write a browser. That was the "conspiracy" you're talking about - but it wasn't a conspiracy, it was more of a strategy on behalf of Google, who knew that they were the only ones that could provide this level of support, and so if they did it, nobody else would be able to compete with them. Even Microsoft gave up on their own engine.
But the only reason Google could do this is because they were deriving revenue from their advertising monopoly. If their web browser was honestly funded, many, many of the features that we see in Chrome today would have never existed.
Also, I'm not going to argue that things aren't better for developers today than they were before. Sure, web development is much easier these days. But at the same time, I think web applications are way too overengineered. There are lots of things that could be done in simpler ways - for example, why is it necessary to restyle scrollbars, or reimplement standard components like drop-down menus with reimplementations written entirely in Javascript? Things like this are just stupid and having to drop support for trivial things like this in the name of making browsers simpler is well worth it in my opinion.