What are the limitations of forming an Engineering union?

Are they really needed? I think even mediocre engineers are probably so versed in tribal knowledge within they firms that if they say they're overworked they could be moved to other departments because losing an employee is often very expensive. Not only that, unlike other assets, engineers get better over time and become more valuable as they become more expensive. We can move firms, start firms, or move laterality to other industries where our technical skills are valued. A Union protects and supports a population with many more unproductive enginneers than a place without one. We are not like line workers at a steel plant as work is abundant and if a bit of effort is made a good work life balance can be had.

I don't have any specific limitations in mind, but I'd review the idea to see what problems the union is intended to resolve. Unions originally existed to resolve exploitation by manufacturing companies. Is the group of engineers you are considering unionizing being exploited?

My girlfriend recently was forced to join a medical union for a new Medical Assistant job. Her "perks":

* $38k / year (In Seattle, which is about $3/hr above minimum wage)

* 2% salary goes to union dues

* She can't get insurance for the first 3 months

* She was not allowed to negotiate salary, even though she got a 4.0 and a perfect score on her MA test. That means she got the same package as a high-school drop-out who got a 2.3 GPA in MA school and a barely-passing test score.

I, as a non-unioned software engineer:

* Make more than $200k

* Always get health-insurance on day one

* Can easily negotiate not only starting salary, but also raise amounts

* Am compensated on background, instead of an arbitrary "this is your first day, so you make the same as everyone else" leveling system.

* Don't have to pay anyone for the privilege

* Don't have to work with shitty co-workers, because they can be fired without the employer fearing retribution from a big, faceless union.

So tell me-- why in the hell would I want to join a union?