I don't mind people looking at my profile per se (otherwise I wouldn't be here), but when they then disappear having looked at your profile over and over, it's like having your own personal stalker - and I've been there thanks, and have no wish to return!
And yes, while the profiles are public, the photos are only available to logged on members, but it seems you can still be logged on but hidden - ie disabled profile - that's what's worrying. These people could be absolutely anyone, and without going into detail, there is a person from my past that I really don't want to know where I am or anything about me.
If people have nothing to hide, then why hide it?