Ouch, did you just disparage an entire discipline and group of people?
If the shoe fits. 
I’ve had the same issue while cross country skiing (and road/gravel riding, thankfully not too much on MTB), but it’s usually older guys and it’s a weird situation to have to be in! As a woman especially I get super paranoid and uncomfortable with someone following me like that, usually I have enough in the tank to drop them but I agree its super distracting. I think what makes it so weird is they never say anything, I usually have to look back and make some sort of indication.
I’ve also been on the other side seeking a draft, but I will ALWAYS pull alongside (or closeish) and ask: “can I get a draft?” I wish they would do the same. 
I hope the shoe is blueberry flavored because it’s in your mouth
That’s creepy and off putting and I’m sorry you have to put up with that shit. You have the right to be left alone. We all have the right to be left alone.
100%
Unfortunately, that’s simply not the case. There are laws we can lean on when certain lines are crossed, but most of it just comes down to basic human decency and common sense. And not everyone who struggles with those concepts is an evil person, some folks are just wired different and/or have mental or environmental challenges in their lives that result in anti-social behavior. Most are harmless, but some are dangerous, really hard to tell sometimes.
Totally. I have not been attempting to argue that there are laws to enforce this, only that there are, or should be, basic manners. Or at least I would like think there are!
To that end I am using the phrase “everybody has a right” in a way that isn’t necessarily hemmed in by actual laws. I don’t think it’s terribly controversial for a person to prefer to control the space in their immediate vicinity. If any of us were walking out in the world and a person came up and stood so close to us that we could smell their breath when there was an otherwise empty room I think a high percentage of people would prefer that person to move away. Why this doesn’t seem to apply on a bike for some people, especially when there is physical risk involved, is mysterious to me.
But I understand what you’re saying vis a vis some people just needing actual laws to be compelled to act with kindness and courtesy. And even then… 
I draft people on the road when I can. Specially coming back from a long ride, it has to be someone that is legit going fast. I would find it odd if that person tells me to give them personal space.
i mean drafting is pretty common. This context of it has varying opinions but in many group rides and nearly all races, what he did was totally normal and in that context you would be the one who’s acting strange.
On a hilly gravel training ride, sure, maybe questionable, but it’s not like he picked his nose, flicked it at you, and questioned why you are mad.
Totally agree about GROUP rides and races.
Agree, as a woman, its pretty weird when you’re riding along alone in the middle of nowhere, and a guy comes up to sit on your wheel and stare at your backside without even saying anything. I’ve had it a couple of times, I’ve either turned off onto a little side path, or sat up and pretended I just got a message on my phone and need to stop.
This, 100%!!
Being on the other side of the equation on this: a simple “mind if I draft?” goes a long ways in terms of the other person’s comfort and security level!
My husband and I were doing a long gravel race in MN and this guy would NOT leave us alone, I had to fake having to pee to get him to go away and stop messing with the flow of our ride (and of COURSE it was near the end with all the hills, no chance of dropping him aargh)!
Normal in the context of a race or with a group of mates you know. Completely not normal outside of that context, when you come across someone you do not know. Ask for permission and respect their response in this context.
Yeah.. I wouldn’t do it without saying something. I have had strangers draft without asking and it doesn’t bother me. Happy to give a tow.
I can see why some would be bothered. However, I can also see why some riders might not know the proper etiquette.