I feel the same way Boofo. It ain''t worthy to spend time and effort in releasing something for free when all you get in return is grief and ungratefulness from the users.
Unfortunately it is not a few but quite a lot of these "bad apples".
I agree with your last statement. But if you look deeper, it is a symptom of a larger problem: vB.org is strongly anti-commercial. Will ungrateful downloaders one day join together be grateful for the tools they receive for free? Highly unlikely. On the other hand, are you allowed to promote your websites containing paid products? No. Why? Being too commercial would make the board spam-tastic, and this will probably never change.
I don't know if you remember, but when I posted the thread a while back asking if anyone wanted paid registration (my first real modification here), you voiced your feelings of unappreciation by downloaders. I took note of what you said and when I released my product I asked for support and... from the few appreciative downloaders, I got it: a tester, two donators, and a few suggestions that made the mod better than I could have ever hoped, before 30 installs to top it off!
The best you can do is get support, have a clear goal, and have a clear mission when releasing the product. My mission with that product is to complete the vBulletin experience, and my goal is to win MOTM.
The difference between installs and downloads is discouraging, and I have definitely had moments of weakness where I considered stopping support, but I have help from contributors and a mission, so I will be ok. Hope this will change your mind.