TNG is comfort TV, similar to something like Friends. The cast have a warm & pleasant on-screen interaction that's very easy to watch. Not many shows do that these days; there's more focus on inter-character tension or complicated ongoing plotlines.
There's a lot to be said for having a warm, fuzzy and satisfied feeling after watching a show.
Yeah, I know the writers were constantly frustrated at the lack of internal conflict among the main characters, but in retrospect I think Gene was right to downplay that for this series.
Not only did it strongly reinforce that "family" feeling, but it really did make the characters seem like they were from a more evolved 24th Century. And it made the show stand out among all the OTHER dramas and scifi shows where the characters constantly bicker and get on each other's nerves.