[kuu]

I think is a bad idea as reading a book. If the only thing you do is that, a lonely solitary thing, it doesn't matter if it's a book, watch a series or play a solo RPG: the issue is not the activity, it's your relation with it.

I agree with you that social interaction is important, needed for a sane life, but at the same time, I consider this as not a bad option for those cases you cannot meet with friends.