Things get harder later on and you have to start thinking that way. The first couple levels are pretty easy so you can acclimate to the combat.
Yep in the later levels the guys start ganging up on you more.
I thought about my combat style depending on my mood:
Do I want to defeat the enemies with minimum time/damage? (some quick-kill tactics involve no button mashing)
Do I start the fight with high/low stance? rush attack? etc. (opening attack plus stance affects combo style and finishing waggle)
Do I just wanna WAGGLE? (finish everyone off with WRESTLING MOVES, hell yeah!)
Like preceding poasters implied, tapping-A with one stance all the time will eventually become totally inefficient and get you stuck later in the game. I thought the game ramps up the necessity for combat variety nicely.
NMH waggle finishers are like playing RE4:Wii with just the pistol for the sake of only-head-shots. Guilty pleasures.