I still think it's stuffty that he didn't give credit to Zapk
Trails and Rising Lava are made by Zapk. Download the gamemode and read the description.txt
He's given credit just now. And if you can easily download the gamemode and read the description.txt and see who made it, then that's all the credit needed.
There's no obligation for Tezuni to have a sign/message in his servers saying "This gamemode/Trails created by Zapk!".
The information on who made them is publically available, Tezuni isn't claiming to have created them, he understandably doesn't want to advertise a notorious user on his servers, and I'm sure that if you were on his server and asked who created the gamemode/trails that Tezuni or someone else available would tell you.
It's not like everyone expects every single Speedkart server to have a welcome message saying "Speedkart created by Filipe/Badspot".
For the most part, this just seems to be a few people trying to police how other people spend their money.
If you have a problem with people donating to the server, then confront the people donating, not the server host. He's not doing anything wrong in having a donation system, even if he is giving incentives for donating.
If there was someone selling turds he's produced, and people are buying, who's in the wrong here? The person selling turds, or the people buying them? He's not forcing anyone to pay for this stuff at all.
I'll be frank and just say that I'm impressed that one member of the community has the entrepreneurial mindset to get some money back for his work and hosting. And if he earns a profit on that, then congratulations to him.