Being a gentleman is an essential life skill. It is a necessary component of maintaining a relationship, building a good professional reputation, and establishing oneself as a solid member of the community.
But by itself, being a gentleman does nothing to attract women - any more than being a gentleman qualifies a man to run a nuclear power plant or manage the Yankees. It's just a minimum standard of civilized behavior.
Attracting women in the post-feminist era is a much bigger game, with a complex set of guidelines. The man who knows how to attract women can choose to behave like a gentleman, or not - it doesn't really affect his attractiveness, though failing to be a gentleman might negatively impact his ability to maintain relationships later on.
The process isn't simple at all. ;)
If he is not a gentleman, where's the attraction...??
When you are attracted to a woman, is she sitting in a public place picking her nose? Is she still attractive?