Bug reports.

Another person who doesn't understand what free-to-play is. The vast majority (which, in turn, attracts another majority) are casual players who will not pay under any circumstances. Making something from the existing functionality paid will ruin the project.

Another person who doesn't understand that if the project owner doesn't get any profit from it, the project will eventually die. Probably sooner rather than later. Introducing a fee for the online lobby is probably not the best idea, but some way to monetize it needs to be found. Donations in their current form are unlikely to bring in much revenue.