i read on here to be careful of a few houses..

I was at a summer event for a few houses that may be considered "middle" by what I read on here, and after mentioning to them that i was looking into delts, and theta chi they told me to not bother with them because they aren't what they seem and to be careful. they said a top house like them is not worth joining because of what it takes before you are considered a memeber. then read on here some of the same type of stuff...what does this all mean?