I agree all the time interaction is bad, some down time is good. Though some of the best interaction as well is forced. When players are just forced upon eachother and have to make do. As that shows what your characters are really like in extreme situations. 

They also shouldn't be prolonged to the point where it seems pointless either. I mean if chars are going to be solo most of the time and then in a group for a short period of time it isn't really worth it as far as I am aware.