I've never been a big fan of fighting games. I don't enjoy button mashing much, so fighting games and others that use button mashing as any sort of legitimate tactic are lost on me. However, I don't mind hack-and-slash games so much, though sometimes they do tend to get a bit repetitive.
What I like to see in games with button mashing is the sort of thing used in games like Kingdom Hearts. Button mashing gets you somewhere, up to a point, but after a while you need to look at other tactics as well. You try button mashing in KH and you'll do okay against all the Shadows and Soldiers and Dusks, but the bigger opponents are going to swamp you. So what does the game do? QTEs in the form of Limits, which actually work really well in the combat mechanic, and specific strategies that you can use against different enemies. In the Journal tips are given to beat opponents without having to button mash.
Kingdom Hearts is just one example. It's not a fighting game, true, but a JRPG. But the point still stands. Button mashing is no indicator of skill or talent. Anyone can hold a controller in one hand and press buttons willy-nilly with the other. What games need to do is go the KH route and use different tactics to defeat different enemies, so that whenever you're in a fight you are forced to analyse the situation quickly and come up with a way of beating your enemy. After all, it surely can't be that much fun to beat the pulp out of your controller, right?