Up to and including Tekken, fighting games were primarily about being /fast/.
Speed was everything - few games had reasonable low moves and all Virtua Fighter's combos seemed to involve left-right-left-right [pound button 10x].
Tekken 2 changed all that. Now you had to be /good/. The combos are truly difficult to pull off, and not because the button combinations are hard - it's because timing is everything. But when you get it right... oh my.
If you haven't seen or done Baek Doo San's Wing Blade/Hunting Hawk combo you haven't seen true beauty in a fighting game. Yeah, it's hard. Yeah, it's supposed to be.