It's annoying that my feudal society that has allowed only one gender to inherit for hundreds or thousands of years suddenly decides that the other gender can inherit. They wouldn't just change their succession because they made it to space. It also annoys me that while playing imperial humans my heir can be white while my leader is black or the other way around. They are clearly not closely related. I have no problem with having leaders of other races but having heirs just makes it hard to roleplay.