This is really a problem of unintended consequences. And it's not "union rules", it's a collective agreement that both the union and management sign off on. Union shop or not, we can all point at absurdities in work life - just as many come from management in my experience (which doesn't include much work with unions).
It's a bit like the tax code or some complicated piece of bureaucracy. Some of the stuff in there sure seems stupid but you can bet it was put in for a reason that, at the time at least, looked sensible. In the case of things like "only an electrician is allowed to do that", it's a pretty safe bet that at some point in the past management tried to do an end run around the agreement and have cheaper labor do something they weren't trained or compensated for. In the US at least the system is so adversarial you end up with hard lines being drawn on both sides.
No, it's "union and company rules". The nature of a negotiation is that both sides have agreed on the result. Getting people to accept calling this sort of bullshit "union rules" is propaganda.
The alternative to enforcing rules pedantically is enforcing them arbitrarily, which is what happens in non-union environments. One set of rules for Billy, another set of rules for Sally.
