I disagree. That's not how you build a team. Also, senior developers who can't pair program, aren't senior developers. That means you can't communicate, or at least you don't want to, even if it's talking about code you don't want to. That's not how you become a lead/architect.
Ah yes, the cliched "if you don't do X you can't call yourself Y" shtick. I know many senior developers that don't pair program. Why? It's inefficient and they get significantly less done. Not to mention, you have no room to experiment with different approaches because you've got some person sitting next to you and human emotion kicks in and they feel like they're being watched and judged at every move.
You know when pair programming is endorsed by the senior developers? Root-causing bugs.
I can communicate very well, and am helpful as I can be when people need it. But slow-as-molasses pair programming with an 8nexperienced junior sounds like hell to me.
One can be an effective leader, communicates well, designs and architects large system, mentors junior developers, inspires them to learn, coordinates development effort, sets up development processes and standards, and develops awesome software without doing pair programming.
Pair programming is not the only and true way to develop software. It's just some passé imposed by Agile advocates.