If the world really needs more escalator mechanics, then salaries for them will rise commensurate to demand and people will train to become escalator mechanics. Until then, they'll continue with other pursuits that are more profitable to them. This is how things have always been, unless you want to reinstitute medieval guilds, and I don't see a problem with it.
Generally, campaigning to make people to do something out of a sense of moral propriety is the wrong approach to creating change.
Generally, campaigning to make people to do something out of a sense of moral propriety is the wrong approach to creating change.