Slightly off topic but two of my many pet hates are watching people start an older type engine that has a "tickler", the little plunger that holds the float down until it starts to flood to enable cold starting, I have seen those "ticklers" receiving multiple stabs as though it was some kind of pump, in the old days of brass floats in the fuel bowl you could see the dents received by those actions.
The other is watching so called professional motor engineers on TV with an open ended spanner used the wrong way around, so instead of using in it's strongest position when moving a tight nut or bolt in much the same way you use a Stilson so it has a wrap around action with the loading on the thicker part of the spanner, they do the opposite. This is probably why I still have my combination spanners from over fifty years ago, that and the fact they are Britool.
I describe people like that as "mechanically unsympathetic".
Apart from "moaning gits" like me does anyone else have pet mechanical hates?
I have just thought of another, people trying to undo tight drive shaft or wheel nuts by pulling upwards on a bar as though they are trying to lift the vehicle off the ground, when a little common sense would tell them to put their foot on the bar and use their body weight, if using a spider wheel brace they can still pull with their hands if needed, why work hard needlessly?