I really hate it when people act this way, now I feel the obligation to try and read their mind and figure out if what I'm doing is upsetting them or not.
The responsibility to be socially aware is your own. The responsibility to not put people in awkward situations is your own. One of the many reasons not to flirt with people in service jobs.
I find this concept questionable. There is a difference between someone who is legitimately stalking someone who very clearly does not want to be followed around (and they are aware of this!), and someone who is being really, really awkward (but totally unaware of the pain they are causing).
What would you suggest the socially awkward person who doesn't understand that they're stalking do? You can't simply wish people were more socially self-aware, and to do so ignores a very large population of people who have trouble with social situations for reasons beyond their control.
A difference to whom? Because I'm pretty sure the stalkee probably thinks they've been clear, and the stalker probably thinks that they aren't being a nuisance. The impact is roughly the same, you scare, creep out, and reduce someone's quality of life.
A large population of people are not held accountable for their social ineptitude, which yields no incentive to be better. Reasons beyond their control is also something I'm skeptical of. I've known plenty of autistic people, and the thing that has separated the genuinely kind from the rest had been a large amount of effort poured in to becoming more socially aware. The attitude we have that some people are above reproach doesn't really help anyone.
I'm not advocating for putting people above reproach. And I'm alright with people being held accountable for social ineptitude.
But I draw the line at awareness: are they aware that the person doesn't want to be communicated to? I'm not interested in whether they think they're a nuisance or not (no one will ever admit to being one anyway), but having enough social awareness to understand that you are making a mistake and then doing it anyway is where I think "stalking" exists.
Simply being "inept," I don't know if people can be held accountable for that. I personally couldn't blame someone who was too inept to understand that they were talking to someone who didn't want to be talked to. But once someone has specifically said they don't want to be talked to, it's pretty obvious.