I am convinced from my experiences doing DIY auto repair that the jobs themselves are all fairly simple, it is dealing with stuck bolts and bolts that are hard to get to which turn the job into hours of work and frustration.
Also in meatspace you can't hit 'undo' or 'git reset --hard' .. I hate that :-)
It's kinda like how (in the days of old, at least) when you built a PC, if you didn't cut yourself and spilled a bit of blood (usually on a sharp case edge) - you were doing it wrong.
Instead, you have that one tight bolt you're wrenchin' and pullin' on - then suddenly it breaks free and WHAM, your knuckles get busted on the crossmember (or something else unforgiving).
Which is why, if you have the ability (leverage) and room, it always better to push on the handle of the wrench with an open palm or loose grip - that way if the bolt breaks loose, the inevitable won't occur...