Ah yes combos. Truly the most skill intensive mechanic in any game. Only the greatest of the great can handle pressing the button highlighted on their UI...

All your effectively done is once again tell me all DPS have a rotation they follow for optimal output. Or put otherwise, they're following a script. Your original statement for why healers aren't complex is that their play style is scripted. But you yourself just stated that DPS are the same...

(Should we also go into how a healer playing optimally and pushing as much DPS as their healing requirements allow make DPS job easier?)