Why are her meetings and work obligations any of his business? 

Have you ever had a coworker who gave their all to the company, but ended up getting little to nothing in return? Growing up, we were all taught that if we worked hard and played by the rules, we would be rewarded. Hard workers got good grades, got into top colleges, and had a guaranteed future in whatever field they chose! It's a sad reality that hard work doesn't always pay off in the working world. Someone can grind in their position for years, sacrificing their personal life and time with their family, only to never get the promotion or raise that they objectively deserve. One of the best skills a working person can develop is gauging whether their company has room for them to grow. If people around them get promoted after a couple of years of good work, it's probably worth sticking around and trying to get promoted as well. If their coworkers are constantly getting burnt out and leaving the job because no amount of hard work will ever be good enough, it's probably time for them to start updating their résumés.

It's hard enough when you have to work harder than everyone else to try to make your bosses happy. It's even more frustrating when your coworkers perceive you as being a try-hard who cares more about your work than you care about socializing with them.