Lior:
1) Accepting and throwing out are different, even for a yeshiva.
2) Shul membership and being in a yeshiva are different.
A yeshiva bochur is the responsibility of the yeshiva, but
a potential shul member is not the responsibility of the shul.
What may happen to a yeshiva bochur if he is expelled is not at all what may happen to a grown man if a shul doesn’t want him as a member.
3) It would be better somewhere noisy where no one cares about what he’s doing. If a person cannot be considerate of others,
perhaps he should stay home…
(Phlegm in the throat is presumably an effect of a
temporary medical condition, but his attitude towards/awareness of others shows through how he handles it.)