I tend to view enemy resurrections as a chance to develop an adventure.
How would an evil army react to their warlord's death? They'd probably side with the PCs to keep him from being resurrected--after all, the new evil warlord that seized command upon his death would have to fight him for command of the army. If he's in a cozy spot to hold the territories they've already taken, he has to have some incentive to want to become a subordinate again. There's enough political maneuvering there to base an adventurer on. Maybe the new warlord reveals that the old guy with get raised from the dead at Evil Temple, LLC (who sponsors the evil army) on the night of the dark moon and tells them about the secret underground tunnels to get into the temple and stop the resurrection. They're both in a prime spot to benefit from the PCs stopping it, but the new evil warlord can't attack the temple himself for appearance's sake--they're supposed to be his sponsors, after all, but he certainly doesn't want to lose his new office. If the PCs can stop the resurrection, new guy promises a cease-fire and allow diplomacy to resume. That's an adventure with consequences for failure if I ever heard one, especially since the PCs have to work out their priorities and decide who they can trust.
Some players do indeed feel that raise dead and similar magic are PC-only resources. I've seen many players that feel like raise dead should be available at 1st level, and friendly NPC clerics with gobs of gold and diamonds should gladly cast it for any schmuck adventurer that had smart-ass comments for an orc chieftan or decided they should free-hand climb a 100-ft cliff without taking 10 on their Climb checks. I call shenanigans on that. In my opinion, raise dead isn't insulation from the consequences of stupidity. I view it at sort of like insurance--if you've prepared for the possibility of a future tragedy, it becomes manageable instead of disastrous. At higher levels, it's expected because the threats the PCs face can kill you instantly.
I've also seen players object to NPCs using cure spells, potions, and other items. (Of course, they also balk when I offer to remove cure spells from the campaign if they don't like them.) Same sort of thing in my opinion. I don't understand the idea that PCs should get things that NPCs can't have.