It is not uncommon that the people seeking to be mentored are lazy to put any effort into learning. It is also not uncommon for a lazy manager to put an effort to see how much this senior programmer is mentoring other. It is also not uncommon that this senior person might have learnt all his/her skills from books/discussions forums etc. Some of these senior programmers put their personal time because they are passionate about their craft. Please don't make assumptions that anybody who is not so pleased about sharing his skills is not a team player. Oftentimes, a lazy manager pits team members against each others. You sound like that horrible manager to work with. If I were your team member, I would find another manager.