Should My Parents Divorce After 30 Years?

My parents recently got into a huge fight over the fact that my mother had one day off after working 6-7 days a week and wanted to relax, and my dad who is currently unemployed and collecting unemployment had the nerve to call her a lazy ***. She pretty much snapped after years of his hypocrisy he’s done things like call her fat when he’s fatter, attacked her income when he makes less, and told her she’s not working enough when he’s not currently working at all. This sort of crap is long standing. He’s got a Jekyll and Hyde personality if there ever was one. Sometimes he’s nice, fun, jovial, enjoyable to be around and other times he’s mean, nasty, verbally abusive, petty, angry for no reason, accusative, etc. You never know what kind of personality you’re going to get and living with him is like living on top of a volcano while walking on egg shells. He does work but only 9-10 months out of the year and makes alot less money than she does but has tried to kick her out and get her to leave repeatedly in spite of her being the bread winner. He’s missing part of his brain obviously and has bi-polar disorder. She’s likewise tried to kick him out but he won’t leave even though he’s frequently complained that he “hates it here” “wants out” and “has to get out of this house”