I like working on my own stuff because I know its done right. I don't skimp or cut corners, and am usually thorough, where I think mechanics just throw crap together as fast as they can to get onto the next job, especially if they are paid by flat rate instead of hourly. When I was 20, I worked at a Firestone as tire changer and lube tech. I seen some of the stuff other techs did to make money.
I'll never forget the day, an alignment tech said, hey come here, let me show you how to make some money. You see this idler arm? Its common these are bad. Flat rate pays 1 hour to change it, but it only takes 10 minutes when you have the right tools, so here's what you do. The tech took an air hammer pickle fork, and with it bolted in place, he air hammered the joint and trashed a perfectly good Idler arm. Then he goes out in the lobby and gets the owner and brings her into the shop and shows her the damaged idler arm. The lady was scared shitless when she seen the slop it put in the steering. She asked how much it cost to be replaced, and started crying because she didn't have the money to get it fixed and refused to drive it that way since the tech scared the hell out of her telling her she could lose her steering on the highway. She told him to go ahead and fix it, but didin't pick up the car for 4 days since she had to wait til payday to come up with the $80 to cover the bill. The tech admitted he picked the wrong person to F over that day and said he looked at the invoice and it was a credit card customer, but didn't know the card was maxed with the 2 tires and alignment she originally came in for.