Yes, but the unban system is open to corruption. Some servers, *MineLink* for example purposely ban you so you have a greater chance of buying an unban from their shop. You have a point but your thinking just doesn't consider kids or teens that hardly have any money. I'm not saying all server should give all their money to the plugin developers, what I'm saying is at least give them credit for making the plugin. Some servers try to hide that.
Those servers may make more than enough to host the server, but you don't know that they aren't spending that money on their dedicated hosting (can cost hundreds of dollars a month), website hosting (again can cost 20-50 dollars a month), possibly paying staff, developers, and graphics designers can also be costly. Even if they make more than that (which I doubt the servers you reported were) then you still don't know what they're spending the server money on, they could still just be paying the server off monthly with it.
Nup those servers make a lot of money each month. And they already have graphics.etc. What I'm really unhappy about is that servers are selling unbans, paying money to get unbanned is just unreasonable. Technically, they shouldn't be making any profit as most of the plugins that the servers I visited have are public plugins from bukkit.org. Instead they should be donating to the author who made it. Pay to win is ok but I'm talking about unfair advantages such as you getting a machine gun in paintball and speed 5. Besides that some servers limit who can go where on their servers, now I'm not talking about development servers where only staff are allowed. I'm talking about servers where you have to donate.etc to be able to play on it.
This might be necro-posting but I want too post my opinion on the eula
I think mojang should start enforcing the eula. I have reported a dozen of servers. 20 to be exact. Most of them with 100+ players. Mojang has done nothing nor have the offending items have been taken down. I personally dislike these servers that have greedy owners. They earn more than enough frm the donations to pay their hosting bills. What is this then? The owners are getting greedy.