I want to push back against this a bit because you used the word "expectation." Yes, I strongly agree that bug bounties are
one way to achieve and demonstrate a certain level of expertise in information security, especially if you are trying to break in. However, don't make it more than a job for people who just want to do the job, and don't arbitrarily make it the whiteboard of the security industry.
My best colleagues, the people I most deeply respect and the people who inspired me to work in this industry all neglect bug bounties. They mostly don't participate in them at all. Bug bounties are usually pursued by people who have the free time and bandwidth for them. For the most part, most security consultants and engineers do not actually engage in them because they are already highly paid. This is why you most frequently see bug bounty participants from countries other than the United States and Western Europe.
Those that do have a full-time position and also engage in bug bounties certainly have a commendable passion for the work (or sometimes more accurately a workable formula for getting to low hanging fruit in new programs first), but please don't expect all or even most skilled security talent to adhere to this rule. Many people enjoy being skilled without sacrificing work-life balance. Just as not every software engineer needs to contribute to open source or have a GitHub profile, not every security engineer needs to have badgers for every company they've hacked.