To those asking why people would cheat and that it would obviously become boring in the long run: it doesn't for the cheaters. They'll simply get used to it and maybe even convince themselves that it's somehow not unfair.
In Dota 2 there are a lot of people who keep buying highly ranked accounts because they're completely convinced they deserve to have high MMR, and the only reason they don't is because of "being in the trench", some vague idea of being stuck in a trench with bad players who make it impossible to win for you, no matter what. So they buy high MMR accounts and, of course, proceed to lose about 90% of the games they play. Afterward, they finally release they were wrong and... Ah, just kidding. They'll still remain delusional and maybe repeat the process, even.
Seriously, you cannot underestimate how delusional many players get about their skill level in multiplayer games. They'll convince themselves that they have a right to buy high-level accounts, cheat or do whatever else. It would be nice if it were just people "trolling" others for a bit, but it's not the case.
Their delusions are usually also quite apparent when they do get caught, as visible in examples from this and other threads.