> I find the GPL 'free software' license to be a lot less 'free' than other kinds of open source licenses in terms of what you are allowed to do as a user of the software.
Quite the contrary. For users of software, there's no better license than strong copyleft licenses.
> with GPL, you do not have ownership over any derived work that you produce
This is false. You are free to produce derived works and keep them to yourself, or even to your organization. No need to share source with anyone.
If/When you share the derived work, whomever you distribute the derived work to, they are now a user. You have to give to that user the same rights you got: full source code and GPL-provided rights. You do not have to give those out to "everyone", only to those to whom you distribute your derived works.
> This is a weapon to allow big corporations to sue small indie developers and startups who are trying to compete with them. The balance of power is asymmetric. Only corporations have the money to legally enforce GPL licenses
If not via the law, how can rights possibly be enforced?
Also, note that the GPL has been enforced — for better or worse — by individuals against far richer corporations. This is, of course, only because of the fear of the law.
> Also, the creator of the software is allowed to keep their own derivative work private (because they have copyright) but no one else can (everyone else is bound by copyleft).
As I said above, this is false. Your changes are yours, and you retain copyright on them. Code you didn't write, of course, is not under your copyright; but you still have the full rights granted to you by the GPL to do with them privately as you please.