I spent fifteen years in the trades and worked with many ex cons in that time.

They were fine. Some were great, some were bad, they weren't any different than people with no criminal background as far as work performance goes.

Trade work isn't that mentally demanding 98% of the time anyway, especially at the apprentice level.

Bullshit and excuses and a sense of moral superiority. That's what they want. An excuse to have a second class of citizens to feel superior to. We don't have an incarceration, recidivism and institutionalization problem in America because it's an unsolvable problem. We have one because the traditional power structures wanted a means to control the working class and a new crop of slave labor, and they have run a misinformation drip into those easily influenced by feelings over facts to keep their tactics popular despite overwhelming evidence from the rest of the western world that rehab works if you just put down your "justice" boner.