The thing is, yeshiva is considered a for-profit venture. These people are paying tuition, and the whole point of these kiruv yeshivos is that the parents won’t have to or can pay less. You’re getting tuition money- why should I help you?
So then the yeshivos make dinners, which are only useful if the parent body is already wealthy, while if it was it probably wouldn’t really need the dinner quite so much.
And thus, you end up with the yeshivos struggling to break even.