The main motivation for this is bringing more revenue from banned players buying accounts...
Not even two full sentences in and you're already spreading your own deception.
Riot doesn't make any money off of bought accounts. The people who sell accounts do, which means less revenue for Riot. Unless part of your "detailed posts explaining Riot's corruption" involve some tinfoil hat theory about Riot actually running the account-selling sites, in which case...
No. Just no.
...and buying RP for xp boosts and re-buying champs/skins from banned accounts.
When Riot issues a permanent ban, they do so to make the player leave their game. They can't really stop them from coming back, but they hope that they'll leave on the merit of having lost all of their progress.
If, for some reason, they decide to come back and spend more money (which is wholly illogical, nobody in their right mind would do so unless they were going to actually obey the rules the second time around), then that money is spent at their own discretion. Riot doesn't encourage them to spend money, and there's no downside to not spending money.
The solution to BM is muting the toxic player and it's AVAILABLE, it has been for ages...
I know, right? Why do people keep flaming instead of muting and reporting players who upset or annoy them? It'd be so much easier for people to avoid bans if they just muted instead of getting into a flame war.
Unless you mean that the players doing the BM are the ones getting punished, and that Riot should rather employ permanent chat mutes instead of suspensions...You do realize that wouldn't work, right?
...there is no solution to fixing BM, it's part of life...
No, BM is not a part of life. That's like saying "murder is just a part of life", so we should just let people run around murdering each other. BM is a side effect of having civility, morality, and the expectation of respect. You still haven't been remotely clear on what you mean by BM or how it gets punished, so, I'm going to assume you mean "flaming" and not "BM'ing".
Either way, you've done a poor job of "exposing corruption in Riot" and a stellar job at making poorly-founded and ill-explained arguments that don't even work if we assume that they're right.