There's no reason; its a personal choice. I use a Mac for development because its closer to our production environment then a PC would be, and because, for me

There's no reason; its a personal choice. I use a Mac for development because its closer to our production environment then a PC would be, and because, for me personally, using *nix on the desktop is painful. If you prefer to work on Ubuntu, then more power to you. If it didn't bother me, I'd do the same as it would be even closer dev <-> production.