Is it "abuse" when someone picks Dhalsim in Street Fighter and beats the **** out of you from a full screen away? Is it "abuse" in League of Legends when you constantly pick a champion that is overpowered in the current patch?

No, it absolutely is not, because you are playing the game by the rules that the game has set for you, and everyone else playing the game is able to make that same decision. Should they choose to or not is entirely their own decision.

Here's "abuse" in towering:

• Lagblocking
• Speed hacking and hitting the flag from 100 to 0 in 2 seconds
• Finding a glitch that makes you unhittable and using it to steal towers from guilds

It has absolutely zero negative effect on the game whatsoever when people make a guild, tower with it for 1000 hours, and then make a new one. Literally none. The real question is, why wouldn't you do it? Because you don't want to? Okay, well they do.
That's like me crying about people who spar in the side rooms and pushing for staff to make it a requirement that everyone spar in one room, simply because I don't agree with their choice to only spar bad players. Dude, my ego is pretty big, but I'm not stupid. People can do whatever the hell they want so long as it isn't hurting you or the game.

Not to mention, even if it was in staff's interest to limit how many guilds any particular player can lead to 1k, there's no realistic way to implement that. How are they going to do it from a scripting perspective? Furthermore, why would they?