I guess the advantage of a Bond movie is you pretty much know all about the characters from the start, so the film can be off and running. Even the antagonist's character is pre-known...simply a variant on a mega rich-twisted guy (w henchmen) who seeks world domination? Hitch protagonists are simply "the innocent everyman who is framed, and must get the McGuffin to prove his innocence" (a setup which takes about 5 min, followed by a chase across Europe/N. America and a few National Parks?) I suppose the advantage of casting a Grant or Stewart was their character was "pre-known" (assumed to be clever and noble), thereby giving more time to "the chase".

Re: female Ian Fleming characters, true they're not of the more-noble Hitch variety, but in all my years, I don't think I've ever met a woman (church girl, college-feminist, etc) who didn't aspire to being a Bond-girl. In fairness, some seem neurosurgeon or astrophysicist-hot, even P. Galore an accomplished pilot (as such, a sorta G. Steinhem perfection, except they seem to die-off in droves).