would that ever happen if they didn't meet regularly?

Never said it was rare. Once or twice a stream is pretty regularly given that he streams nearly every day and streams twice a day most days.

Even if he only picks a booster, he is getting help while everyone else isn't, that's not fair since nobody else has access to it.

Yes, but the likelihood of one small item completely changing the outcome of a game is pretty small. One attachment or one boost or a vest with one less hit of damage matters very little when you play with top notch game mechanics and you rarely get heavily damaged. Remember, we're talking about the best of the best in the server here. Choco specifically gets countless kills where the other player never gets a shot off. He kills with less bullets, takes less damage, heals less, has better recoil control, etc. than most other players. One item doesn't change his game.

If you are ok with it, good for you.

I never said I was. I'm not defending shopkeeping or even ChocoTaco. But he's the only streamer I've seen who has regular interactions with a shopkeeper so, as I said before, this is my only example to draw from.

You claim that this helps get new players yet it only happens twice per stream at most. If people get to play the game for watching streamers (which they do) it's not because if the shopkepper but because they like the gameplay.

This is not what I said at all. I said that policing things like this leads to less entertainment and less interest in the game both from the streamer and the viewers.

If a viewer loses interest, he might watch another streamer. If a streamer loses interest or viewers, he might play other games that are most interesting to himself or his viewers. If fewer people are watching, or if the game doesn't look fun anymore, fewer people are going to gain an interest in wanting to try the gameplay themselves and thus the game begins to suffer.

People get deeply connected to the streamers they want and form their own personal opinions to match. I guarantee you that when WackyJacky or Shroud or Choco or Doc or hundreds of other streamers die to a player with horrendous ping or die to major desync issues or die to ridiculous bugs, their viewers start to take the same side a lose some interest in the game due to the fact that it's "broken" or "trash".