Wow... It's like the lady who thinks her reflection is fake... https://en.wikipedia.org/wiki/Parable_of_the_broken_window
Well, there would be much fewer of glaziers around, and the panes of glass would also be priced much, much higher than they are today.
And it's not like being a glazier is a person's identity and an inborn destiny, is it? There ain't no e.g. limeburners any more yet we manage somehow.