I've thought about this a lot as I've worked across both B2B and B2C and wondered if it makes sense to specialize and how transferrable skills are. This is also something I've asked many leaders and mentors. The overwhelming advice I've gotten is to focus on being a good marketer and not focus on B2B vs. B2C - instead, think about the types of problems you're interested in solving, the day to day work that most engages and challenges you, and how much you'll learn in a certain job. Additionally, marketing leadership roles often span both B2B and B2C, so having a good knowledge of both can be an advantage.
When looking at candidates, I think strategic thinking and willingness to learn are the top traits I prioritize - whether the candidate comes from a B2B vs. B2C (or even non-PMM) background is secondary.