Rito doesn't punish champion select trolls.
Wrong, they do punish them.
Losing a game on purpose or picking a jungler when you're support, is a punishable offense.
HOWEVER: For that to happen, there has to be a report. If you forfeit the game, there is no report. So, what you are doing here, is kinda a self-fulfilling prophecy...you say "They don't punish them"...and hence you don't bother reporting.
You see the problem with that?
but if you point a single finger against this troll in game, you get banned.
Wrong. There is a finger called "report-button". This you can point however much you want, and you wil not get banned for doing so.
Why would I suffer 20 minute before losing my promo. instead of just losing it?
Because games have been won with Trolls. Games have been won 4v5. Games have been won with an AP Garen as support (The latter I know because it was me playing it. Don't ask. Season 3 was weird at times.)
If you just go "F... it I'm not even going to try...well, then your complaints are pointless:
- You decided to give up, and then you complain about losing.
- You decided to take away the possibility of reporting the troll, and complain about him not getting punished.
That's simply not how the world works.