Vortex Spring, FL, where I've done quite a few solo dives, doesn't have any issues with solo divers. It *does* seem somewhat strange, however, when you're on your surface interval sitting near an OW class as they're lectured with the "always dive with a buddy or the Great Destroyer will track you down and digest your entrails" speech.
Regardless of the speeches (during which I try not to make eye contact with the students, out of deference to their instructor), I've never had anyone, student or instructor alike, say anything to me about my solo diving. Quite often, I've been asked about my slung pony, and I've had conversations about many a topic, but solo diving itself seems almost to be a taboo topic.
A few other places (springs, jetties) around the area, I've been more or less completely ignored (other than a mom telling her cute little toddler, "See, that's what mommy does when she goes scuba diving"). Frankly, being ignored is fine by me, as it's almost as peaceful as some nice, unperturbed bottom time.