May just save you from The Plague and other such diseases.
(Side note: Prince can’t be too happy about the background music in the above clip).

(Photo by flickr user eszter)
You’re friggin’ welcome.
* - Because this would be far too practical.
Don’t blame the union. It’s only serving as protection against mass layoffs, child labor in the subways, abusive work conditions, etc. Union contracts aren’t necessarily written with felons in mind.
Do you honestly think that in this day and age, with as much oversight as there is, the MTA would get away with employing children and exploiting their employees? This isn’t the 1920s. Many labor unions have outlasted their usefulness, and now they defend even the most indefensible, as their main purpose now is to protect their employees at all costs.
You almost got it. The main purpose of a contemporary union…is to sustain itself. To a fault, yes, they seemingly do so at any cost.