So companies looking for electricians or machinists are competing with companies looking for IT managers and the like. Not only is the pay much less than these people could otherwise get, the jobs are more physically demanding and often times, less flexible.
It's going to be hard to entice workers who already make 60+k a year doing a job with a lot of flexibility and downtime to take up a more demanding position. People love to talk about how much tradesman make, but the generosity of their salaries is often over-stated and ignores the seasonality and volatility of these jobs.
pass a drug test
not be a convicted felon
have reliable transportation
show up consistently(i.e. reliable childcare)
And if you fall into one of those categories good luck.
have one of your last jobs be exactly that same technology as what the company is working on, nevermind how many other similar technologies you've worked on and learned on the fly.