I think first and foremost is manners. If you use you should thank or acknowledge. It has little to do with doing it from the heart or not.
If I see someone on the street who needs my help, whether helping an old lady across the street or opening the door for someone or helping someone who got hit by a mugger, I'd expect that person to say thank you. I didn't do it to hear that person thank me, but I'd be put off a little if they didn't at least say thank you. Simple manners.
"Yes and no", for me.
By helping out, you always get the karma boost anyway (if you believe in that) and the feeling you did the right thing.
Some sick people you are helping may not even be aware enough to thank you, etc.
And again the example of the internet: nobody is thanking or giving feedback to all awesome information that is shared on the net either.
Even it out a little by not expecting good manners.
The other mistake is in the reasoning of "If I got 1000 downloads, at least 200 must be using it and they should thank me!!"
IMO, you just don't know that...!
I do support a callout for showing good manners / feedback if you *are* using it.
But a number of 5 or rather 1000 downloads would show me plenty to be happy for. It's a pretty clear sign.
If you have specific questions about your preset, just ask them if you want that info.
BTW: I *don't* support the "it's just a bunch of parameters" reasoning
I have more respect for preset developers than that.
Also... look at yek for example.
I would guess he's now in demand as a beta tester, globally respected, can get good deals, built friendships, ...
All by hard work and generously sharing w/o demanding "thanks", but seeing it as a way to archive for himself, giving back, learning from whoever *wants* to comment, etc.
Nobody wants a crybaby!