They do it a bit too often, but I don't think they should never do it. Thanks to the new help action, nobody would ever die unless it's a TPK, if they don't target you whe nyou're down.
Its mainly a rare occurrence in D&D. When I DM and start going after unconscious players, the stress level of the table immediately goes up a few levels. You are going after their character. Its impossible to rez at low levels and expensive later. People just hate dying. As a DM the unconscious tool gives me a way to drain player resources and not take turns against the enemy. Wasting your turn trying to hit someone unconscious just means you didnt cast a spell, make 3 attacks with a sword, or any number of things. Its a poor use of action economy and is mainly just a middle finger to the players by displaying that you got this covered. In the game we have scrolls and a rez monster at camp, so its a different dynamic but at the end of the day, dying in video games isn't super fun - and in D&D much less so. If someone dies they want it to be meaningful. Not because 3 goblins just pulled a vial of acid out from under their loincloth and decided to have a melt-the-wizard contest.
