Grind that there dungeon

The more I think about DnD the more I can't fathom how the mechanics work for most campaigns.  DnD is clearly designed around the idea of limited resources that are expended over an adventuring day - that is, a group of heroes should get into a large number of violent encounters in a given day or the system sucks.  This is true in every edition of DnD but spectacularly so in 4th Ed. and Next.  When wizards only get one spell per day (back in 1st and 2nd edition) they are going to be very sad when the second fight happens but at least they eventually end up with a truckload of spells and can keep on going.  In those scenarios the other classes are limitless in resources so only some of the classes some of the time can actually go nova.

Unfortunately the new philosophy of giving everybody daily resources makes this problem much worse in any campaign where there aren't a ton of fights on a daily basis.  If I was running a 4th edition campaign the opponents would have to be utterly savage because the players would simply blow their dailies immediately and end the fight.  They tend to get into fights with important enemies or at critical moments and don't spend eternities clearing out dungeons full of monsters who happily sit in a room waiting to die.  Next is looking much the same because spellcasters get far fewer spell slots, particularly at high levels, and everybody ends up with extremely powerful daily abilities including the thug classes.

I wonder if there really are a lot of campaigns that run with the model that tends to make the DnD rules work.  Is it the norm that the players come to a dungeon and then have to hack through five encounters, retreat for a day, hack through five more encounters, etc?  Especially when those encounters are presumably dangerous this seems absolutely insane.  The heroes really go into each room knowing that if a group of enemies rushes them from behind during the upcoming battle they will all die?  And they do this *five times a day*?  It blows my mind because my campaigns tend to have politics and investigation and interpersonal conflict as the things that consume the most time.  I GM more like a fantasy novel, and not much like a roguelike grind.  Not that I disparage those who like DnD as a grind but I can't help but wonder if they aren't being pandered to despite being a significant minority.

The whole concept of daily limited resources in Pathfinder really makes character abilities nonsensical.  Instead of an ability granting 8 rounds per day of Freedom of Movement it effectively becomes immunity to a huge number of different things.  High level spellcasters are always casting their most powerful attacks.  I don't put much pressure on to memorize a ton of combat spells so casters can safely memorize some interesting utility spells... which is probably a nice thing for them, actually.  The next campaign I run is definitely going to use Heroes By Trade; that will also give me more incentive to keep slamming away at adding content to it too.