It is clearly stated in the game manual that the transfer list is an integral part of the game and one of the primary means by which to improve your team. When I began I also thought that the TL was a secondary thing until I saw teams like Sharman shoot past me in the global rankings. If you want to have a mediocre team, then by all means don't use the TL. If you want to have a good team, then you must train and sell players to compliment the players you train to keep.
Once I scored a basket that still makes me laugh.