I can think of a few reasons: 1) MacBooks are pleasing to the eye. ThinkPads are well-designed functionally but ugly. Aesthetics don't matter to everyone, but

I can think of a few reasons: 1) MacBooks are pleasing to the eye. ThinkPads are well-designed functionally but ugly. Aesthetics don't matter to everyone, but to those for whom they do matter, they are not a frivolous concern. Working in an elegant environment (including hardware) can have a positive effect on one's state of mind. 2) A lot of people are interested in developing iOS apps. This is much easier on a Mac. 3) MacBooks are status items like designer clothing and may make people feel more attractive / successful. Obviously this is not universal but neither do I think it's a negligible effect.