Why can nobody who makes coats sew buttons on competently?

The nice new leather coat I bought only a few weeks ago is losing its buttons at a rate of knots. The first one pinged off on my way to the pub last night, and two or three others already look very precarious. I'm sorely tempted to take them all off, and sew them back on properly.

I would go and be specifically irritated at the shop I bought the coat from, if it weren't for the fact that the last coat I bought had the same problem – the buttons were badly attached and fell off very quickly, but once I sewed them back on myself they've never done it again (and I'm not actually that competent at it!). I'm forced to the conclusion that this is standard practice in the coat-making world, with the consequence that everybody in the world needs to get really good at sewing buttons on coats, except the people who actually make the coats. I'm sure this is the wrong way round.