I could agree that passive checks are somewhat annoying. Especially since at the table you don't use passives that way. The whole point of a passive skill is for the DM to give out info when you are above the threshold.
But for social interactions rolls. Too random?
I have noticed that every social encounter has a "default outcome", and skill checks let's you possible alter that outcome. Saying that "Checks work at the table because of DM interpretation" isn't really valid. Of course the DM can come up with a check and a DC on the fly, but in most bigger encounter based checks he should have a DC in mind from the get go.
I have even heard some prominent DMs online say they usually set one DC for a whole dungeon, every check made is made against that DC.
Another rule for Checks is: Does what the player want to do have a consequence? In that case make a roll, if not let it happen. And I feel Larian has nailed this. Most social rolls has a consequence attached to it, often you can avoid the default scenario, or gain some benefit later.
All in all I don't see an issue with them including checks, in fact I love that they did it, as it makes the game feel more like DnD. I would like to see them visualize advantage better, and maybe make the DC flat and then add the modifier.
