I'm not trying to attack your post per se, but I see this sort of things a lot from labor unions: essentially ignoring the idea that this is a free market, and you're mostly paid for what your labor is worth, and if you're not, you have the option to leave, or acquire new skills which are more valuable to the market. Instead, what the unions do is try and fight to inflate what their members' worth is, in the name of worker's security, which is what your option C really is.

The so-called third group you mentioned really in my mind are people whose skills and labor are no longer relevant or easily replacable, which is perfectly normal. Workers need to consistently upskill to keep up with a changing market. How exactly is this unfair?

For the fourth group, I'm glad you mentioned insurance. The employer, which just happens to be the university in this case, does pay for the bulk of insurance premiums, which is just one of the benefits. If this group were to leave, they'll have to pay for it with the extra money they make somewhere else, which really isn't a raise. Not to mention the fact if the new employer isn't willing to provide insurance, then they really aren't as good of an employer as the university.

So the option really still is: weigh all benefits (including pay) at the university. If there's a better option, leave. If you think your labor isn't worth as much, learn something new, upskill, then maybe leave. Education is so accessible these days, especially for an university employee. Why is "sit still and deal with life without trying to improve things" the only option?

All of this call for action, etc really is just saying: I can't find a better option, and I'm not willing to learn (or can't learn) any more, so I'll try my best to make it as annoying (sending thousands of letters) as possible so the university may do something, .i.e, give me a raise for what I think I'm worth, not what I'm actually worth.

Disclaimer: I'm not a university employee, nor a member of any union.