Two things are involved
1. Either the exchange doesn't carry out any due deligence to ascertain if such projects are legit or
2. Their ieo fee is little to nothing
if the exchange was a top exchange they should attain their softcap at least
I would strongly agree to all your propositions just an additional opinion to that is I think the exchange is a cheaper and less expensive compare to those well-known exchangers so they tend to use it in order to lessen their expenses.