So here is my suggestion on sorting out the crew payment and morale thing:
1. Add in a "counter" that sees how many times you paid or did not pay the salary in a row.
2. First time not paying salary, decrease morale by 30. Second time, decrease by 60. Third time, decrease by 90. Etc.
3. First time paying salary in a row, add 1000 Leadership XP. Second time, add 2000 Leadership XP. Continue until it maxes out at 10000 per month.
4. Every time you don't pay salary, your "paying in a row" counter is reset. So not only does the morale drop, it also hurts your Leadership skill increase.
That would make it more difficult to keep not paying salary, while also making it worthwhile to do keep paying salary.
It would also help with your Leadership not improving quickly enough if you don't play any quests.
Also, how about you, as captain, ALSO getting paid salary? Into your wealth, that is.
Then at least you can get some personal money if without having land or using Divide the Plunder.
If you don't care about that, you can always donate it back to the crew fund.
After all, it looks like that was always the intention:
You can only gain wealth from your salary (if in salary mode) or by dividing the plunder (if in share mode), but you also get a bit of wealth each day from income from
your lands (if you’ve been given any land). Wealth is one way to “keep score” in POTC, but it also helps determine your fame--and famous captains can recruit more sailors.
I don't think that has ever been the case though. Did anyone ever see their wealth increasing on salary mode without having land?