The guy with skills: E who can only kill people is only one of many ways to optimize. There are combat mages, private investigators, underground reporters, eco-activists, burned-out company men, ex-pit fighters, and a lot more. If your main (but not only) concern is optimization, there as still so, so many ways to do it.
But even the guy skills: E who spends most of his points on combat skills is neither unrealistic, nor does it have to be a shallow concept. It's not unrealistic, because the world of Shadowrun has plenty of thugs, legbreakers, and muscle, and despite their numbers they are always in demand. It doesn't have to be a shallow concept, because you can take the concept in many different directions. You can angst about only being good at inflicting violence, you can embrace your inner monster, you can sink into sullen apathy, you can become paranoid, you can become overconfident - and you can grow and evolve into other roles over time.
And if you like roleplaying characters who fail - why, such a character opens up a world of failure for you! A character hyper-focused on combat can fail at everything else! He can struggle with the adware infesting his cheap commlink ("I don't even like troll-on-elf porn! I only clicked on that one link because I was, um, curious."). He can hang his head like a chastened schoolboy when the face has to take him by the hand, and do a bit of fast-talking, to get him into the club past the smirking bouncer who stopped him at the door. He can kick an empty bottle down the hall with a clatter when he is trying to be sneaky, making the cat burglar wheel around and glare at him. He can overpay his fixer to get a gun that is more or less like the one he had before, just with more bells and whistles ("But, but... it's 'The Razorboy's Ride-Along', dude!"). He can pine over the hot elf he is too intimidated to even approach. The possibilities are endless!
