Keep had a whole lot of problems other then just Kalarel being an uninteresting blob of combat, to be fair - but Kalarel was one of the bigger problems. The actual plot was more or less Kalarel attacking the village for...erm, no particular reason. Writing love letters to his minions explaining his plans for...erm, no particular reason. His plan is to open a portal to the Shadowfell where Orcus doesn't have a temple, and even then, the 4e books make it clear that portals to the Shadowfell aren't exactly rare. Mix in a lot of terrible encounters, some horrendously bad DM advice, and what few good nuggets are there accidentally and hidden, and there you have it - the leading argument I've seen against playing 4e in others.
Incidentally, the actual keep in Keep on the Shadowfell? You're there for like a minute until you leave. Yes, there's no keep in the module named after a keep.
But how does this apply to the topic?
At no point in time are any of the monsters given any fluff or thoughts or purpose outside of being blobs of combat. There's a tribe of goblins there to guard against...well, what? A tribe of hobgoblins? Who then guard against undead. Who are guarding against...the goblins, I suppose? Winterhaven itself has exactly zero interesting NPCs. Seriously, the NPCs in Winterhaven are the intellectual equivilant of "Welcome to Corneria."
So what's the point of this?
Namely, that if NPCs are written to be nothing more then combat blobs, they're going to be nothing more then combat blobs. Certainly, the ride skill isn't very useful in an NPC. But daylight or turn undead? Daylight alone can be helpful in establishing a mood - right before the PCs attack, she casts it on herself, highlighting her armor in a beautiful shining light. The five rounds thing hurts Kalarel because the assumption is "The players won't give a damn about Kalarel at all, because they're just going to find and kill him in five rounds." The five rounds assumption works in combat, but it's carried far beyond that. When you actually reach Kalarel, you don't even know who here is - some evil guy opening a bad portal, for some reason? Whatever, INITIATIVE COMBAT!
Ugh.