I absolutely recognize the fact that everyone learns from others and having a space to do that and people who are willing to invest in others is great -- my problem is that it's a requirement and not a differentiator.

Not every good engineer is a good teacher and not every good teacher is a good engineer. The two things are almost orthogonal in my opinion.

The kind of teaching you mention in the second paragraph is second nature to any good engineer. That's a base level realization, possibly even just a component of maturely working in a team as a human being. It shouldnt even be a differentiator between a 'junior' and 'senior' person to begin with, that's just hiring people who work well in teams/understand team dynamics.

To expand more on why i I dislike this requirement, I have seen companies use it only as a barrier to being promoted. "Oh yeah you're up for a promotion but you haven't lead a class on X technology yet". Having a policy like this also lets companies ignore the real problem: inadequate new hire training.

To sum up, the kind of teamwork you're suggesting is vital/good for companies, i agree. I disagree that it's a differentiator between juniors and seniors though.

Another argument is that value (being good at teaching/mentoring other engineers) is VERY valuable to the company, and the pay increase they're trying to offer for people who can do it (well, I assume) is inadequate.