I wonder if the following aspects make the grind more prevalent for parties:
- No or at least unlucky Striker
- Leader focusing on healing (look at the difference between Tactical and Inspiring Warlord)
- Defender with a Leader focus (Paladin, Shielding Swordmages)
I noticed, particularly looking through Martial Power, that a Warlord can grant a lot of extra attacks, sometimes even to multiple characters. Maybe trick to less grindy combats is just increasing the number of attacks and damage dealt out. Sneak Attack, Warlocks Curse and Hunters Quarry might be only usable once per round, but the characters don't hit every time, so a free extra attack can increase the chances for extra damage counting.
I think one of the biggest difference between 3E and 4E might be that focusing on defense in 4E is actually a valid tactic. Healing comes usually in very large chunks - larger chunks then an individual attack typically deals.
But not focusing on defense increases the length of combat.
Well, that's my theory - now, looking back at your "grindy" encounters - what was your party setup?
My Personal Experience:
Yesterday, we had a party with an Inspiring Warlord, a Paladin, a Swordmage (the defensive kind) and a Wizard. No Strikers.
Combats definitely took longer. And while we took a lot of damage, the Warlord just could keep the party up. The Paladin healed himself, and the Swordmage negated damage. But it took a long time to take down two Soldier, leaving Artillery the chance to hit us hard.
Look at this party compensation - A Paladin that can use Lay on Hands to heal himself. He barely used his Divine Challenge (and never to deal damage). A Swordmage reduced damage to the party (that's pretty close to healing). A Warlord giving out Healing Surge triggers as if there was no tomorrow.
But nobody that could deal decisive amounts of damage, and there were very few ways to increase to-hit chances.