Again how could you customize your speed? The only way it went was up no matter what. You could control the rate at which your speed increased but you couldnt stop it.
How does it not customize your speed? This is like saying your alteration skill goes up no matter what because whenever you walked on water it went up. You actively have to choose to sprint, just like you actively have to choose to cast a heal spell or cast walk on water, or pick the lock. Some skills are so common that most everyone will use them to some degree like athletics or speachcraft so they will almost always go up and eventually if you play long enough will be at 100, though you don't have to take the perks that make it awesome.
I mean sure you don't have to sprint ever and you don't have to talk to NPCs but no matter the archetype of the player chances are he will do those things sporadically through the game. There are some skills in the game you can't easily fully stop, but you can slow them down and you can choose to avoid the perks associated with the skills. Look at block even if you have a 100 block someone who takes the improve block perks will absorb a couple hundred % more damage, the same thing would apply here. Even if you get you acrobatics/athletics combined skill to 100 without the perks you only jump X height with the perks you jump 2.5 times higher.
But no they decided to remove an entire style because people out there might play their game how they want too play it and not follow the tracks like a good little closed world gamer. Too bad this is supposed to be an open world game, but hey I'm given 3 options when I bump into the guards escorting the prisoner that is open right, I mean you can't expect them to have any option you could come up with available that would be silly and too open.