Software Engineers have some leverage, but not a lot and not uniformly. The way to get more would be to get better at organizational politics, but that isn’t typically of interest to many software engineers.
In terms of negative effects the companies who resell or provide competing services without approaching the maintainers first are even worse. It's technically legal, but it's effectively a giant fuck you to the spirit and community.
In terms of leverage it's the ability to put food on the table and maintain a decent standard of living that has the most effect. To this end I'd rather see UBI and unionisation over everyone continuing to play stupid games where we all pretend we aren't there to maintain a decent standard of living.
At my company we have a policy of upstreaming changes where possible just for the pragmatic stance of reduced engineer time maintaining forks.