That kind of behavior is less welcome in enterprise environments where they want you to get in line with the top level goals.
From my experience working at Bloomberg, there was a limit to how much you could rock the boat as a dev and in many ways the technology/language choices were limited to the approved stack.
It’s a strange place because it’s fully owned by Mike Bloomberg without any board or other group of shareholders that oversees his decisions. There is a “board” equivalent but they report to him. It’s great in someways like how they’re able to spend so much of their profits on philanthropy but leads to a lot of quirks.
But every organization has its sacred cows, and no matter where you work, if you happen to get yourself into a situation where in order for you to be right, your bosses have to be wrong, it's game over.
My point is that at most presenting a proposal is only tangentially related with a grievance that's important enough to warrant firing someone. No one gets fired for reaching out to their boss and say "hey, I think I can improve this". It's a scenario that's unbelievable.
I understand your skepticism. Here's the thing: pretty much every time you go to your boss and say "hey, I think I can improve this" you are going initially get blown off. Every organization has inertia, and--lets face it--most clever ideas don't really work out anyways.
If you really want to effect change in an organization, you have to champion it. Your bosses are already busy with other things, you have to get their attention and get on their agenda. If they raise objections, you have to find answers to their objections, and ask them again. And again.
How do you know whether you are the heroic technical visionary, or whether you are just "that guy" who never will just shut up and go away?
More to the point---how do you know how to raise the issue to your bosses, and how many times you can raise the issue to your bosses, before they class you as "that annoying guy."
The answer depends upon the politics and culture at your company. Some things are considered rude in some cultures but not in others. If you are politically acute enough, you can sense when you ar going too far, or you are kicking some sacred cow, or interfering with some powerful person's agenda.
In my case, I had always worked at West coast companies, and I didn't pick up on these cues. Am I hard to work with? Am I "that guy"? Yeah, I guess I was, but I have worked at other companies which would have really appreciated my approach.
BTW, I'm not making value judgements here--when you are dealing with somebody else's money, and in areas where there are a lot of government regulations, etc, a more conservative culture is entirely appropriate. Alas, I'm a pretty good programmer, but slow to pick upon these sorts of things. Live and learn.