Interesting to note that in a homily, St. Francis de Sales points out to the sisters of the Visitation (community he and St. Jane Frances de Chantel started) that the life of a religious sister or brother is far more difficult than that of an anchorite. He cites that the former must die to all, including determining their own rule, while the anchorites and hermits have leeway to make choices in their rule and living it out.
This is true. I see it in a hermit being able to be canonical or non-canonical. Also, there are so many different forms of vows and rules--with common threads, yes, but variance allowed.
Hermits are individuals with each seeming to be his or her own community in a way. I admit it would be difficult for me to not have variance.
What he doesn't point out, though, is how difficult it is for an individual to remain on task. And we do see that in reality, communities of hermits as well as communities of religious sisters and brothers do not always stay on task, or remain obedient to their founder's rule. But in the ideal, St. Francis de Sales makes a good point.
Perhaps those called to religious orders are thus called because they are disposed to group obedience and not of the inclination to develop a rule of their own within parameters. Perhaps hermits are thus called because they do have these capabilities given by God in their inherent make-up. I know school teachers who have external locus of control seem to fare better in public schools than the more creative types who have internal locus of control (as researched in a study at USC). It would be interesting to study hermits vs. religious if one had the time or need to verify the surmisals.