Checking ATIS and weatherreports? That's only possible when you are within 30 nm. of the airport. So, how do you check an ATIS-report for the airport you are going to if it's more than 30 nm. away? Lots of airport don't even have there own ATC.
You're right, most airports aren't towered but lots of them have an ASOS or AWOS. Along my last route from Canton TX to Jackson MS I checked the AWOS/SOS of servaral airports along the way. Just because I'm not landing there doesn't mean their automated system can't give me a basic picture of the weather I'm flying in. The day was as clear as they come but the gusting to 30 winds neccesitated knowing what I was flying into. FSS will also give you in-transit weather reports if you call and ask for them.