Sure. A boss fight can be a good time.That’s not necessarily uncommon, with a party of four facing a single enemy. I get dither enemies are common in many games, but one designed so everyone is stronger than you so encounters require coordination amongst the party to succeed, is that like crap game design? How is playing mooks sucked into a strange universe of challenging encounters not fun? Is grinding levels on pointless encounters necessary for a fun game? Only whale hunts seems like something even you might like, why does their need to be encounters with suck ass goblins on the way to the whale?
A lot of mainstream adventures are overloaded with "insignificant" fights, but I think when done correctly (and not overdone), it's beneficial to the game. Let's consider about the importance of mooks from a storytelling and also gameplay loop perspective:
1) They can be used to telegraph the theme of the adventure and the abilities of the boss. (Some skeletons/zombies might indicate the presence of a necromancer.)
2) They can drain resources and bestow lingering conditions on the party that can add to the challenge of the boss fight.
3) They can allow the party to practice tactics to be used against bigger foes.
4) It's fun to feel competent with your character (or daresay, overpowered) from time to time
Random deaths don't contribute to this loop.