Like anything, it's a mixed bag. The folks I've talked to on the local GMRS repeaters have all been pleasant. I got my ham license not long ago and discovered a good community there too locally. Many of the local GMRS users and the repeater owners also have ham licenses and I found out I work with quite a few hams as well. As for MURS, I don't think there is as much a community around it, but I found that it is useful for outdoor simplex comms in the woods away from town where you won't find the band busy with business users.
However, in the next town over there's a group running a bunch of linked repeaters on GMRS requiring paid membership and the impression I get from the outside is that they would put the sad hams to shame.