I can't imagine there being that many jobs critical to public health and safety where there aren't already mechanisms in place to allow for low-risk job action. It's not like there is a glut of suitably trained people just waiting around to work as scabs.

So, yes, the only purpose of this exception is to allow companies to play games with strange and wondrous definitions of what constitutes "public health and safety".

To be fair, this can be a good part of the legislative process.

Create a law that serves as a framework. Perhaps it's overly broad or has loopholes, but it can't really be challenged in court. Once you have legal precedent, you can create follow up laws to fine tune it and protect people in more specific ways.

This assumes you have the political and legislative will to continue to enact laws.

It's not that big. Someone will try to use it when I shouldn't, it'll get challenged in the courts and they'll get a fine and some better clarification.

I don't think it's a loophole at all. AFAIK, most (maybe all?) of employees covered by that exception already aren't legally allowed to strike anyways. So, for example, you don't want a situation where if nurses strike illegally, it's illegal to bring in replacements.

I think it is a loophole but in the original sense. A hole in a castle wall used to help protect the castle (by being able to shoot out of it). It's a hole in the legislation that helps defend it from attack. Ie it can't be opposed for safety reasons, it can't be suspended either for safety reasons.

I think I trust the courts to not let Starbucks off on that, at least.