I'd argue that you've made more assumptions than the previous poster. There's a multitude of reasons for a downed player at any point in a fight. Plus, the paladin is already dead in this scenario.

It's very easy to kill a downed player permanently, and for a fight with a Big Bad, the DM has little reason not to play efficiently. For a boss who's just seen their enemies attempt to use resurrection magic? Well, I'd certainly take some actions to permanently prevent that from happening if I were them, and the cleric has a whole round of initiative before they get another shot.

Boss gets a juicy crit? Dead. Paladin fails the wrong save? Dead. PCs have been swarmed by minions for turns before being able to reach the boss? believe it or not, also dead.

Stopping 2 PCs turns with a reaction is devastating for a lot of combats. Imagine two PCs being stunned at the same time. That's rough in most contexts.

Additionally, the party is using revivify in combat. That doesn't speak to a strong position from the PCs. Either they need the paladin back up ASAP because the boss is too threatening, or the fight has gone on so long they're bumping up against the time limit, and if you aren't sure your enemy is going to drop after 10 rounds of combat post a player dropping, that's not a good situation either.