It's not skills, it's disrespectful. Imagine how Spielberg would feel if you streamed yourself fast forwarding through large chunks of 'Saving Private Ryan' ?
Did you know that speedrunners don't Speedrun games from the get go? They finish them as intended, maybe even more then once and they fall in love with them so much that they try to find a reason to play them more and more and speedrunning fulfills that wish