A better analogy would be a guy taking a taxi 26.2 miles and you coming along and saying, "I hate it when people move a marathon distance by any mode except running" for no discernable reason.
It's the difference between a baseball game and a home-run derby. Nobody's complaining that home-run derby is "cheating" because all the pitches are ideal. It's a different game altogether.
The tool-assisted speedrun people are simply playing a different game.