IMHO, you got just what you asked for at the Triumph dealership. When I say, "I'm just looking and not buying today.", I'm telling the salesman to get lost and leave me alone. Most of them understand that.
When you are just looking and want them to show you stuff, let them know. Something like, "I'm not buying today, but I would appreciate it if you could tell me more about xyz bike.".
I try not to waste their time, and don't want them to waste mine.
I am going to give my best shot here to explain. IMO, it is wrong in your part to assume I am telling the salesperson to get lost. I was letting him that I am not buying one right now, but would like to check them out - which means give me some info on them, let me test drive one. Even if he understood that I am asking him to leave me alone, there is a way you express it.
We were flat out told NO on wanting to test drive a Triumph speedmaster. And I am not saying he does not have a reason of saying know, he may have reason to do so. And I would not make the comment about the dealer being unfriendly if his demeanor of communicating to me was more welcoming. I can assure you, in no way I was being a jerk or was disregarding the person I was talking to. It was his attitude of telling us we cannot test drive that turned me off. You can be polite in your way of telling a person no and you can still come out of the shop not feeling like you have been treated bad.
Again, I am want to point out here is that the whole experience is not as simply as I stated in the above two paragraph. If I am to re-create the exact experience, I will have to write a whole wall of text which will be waste of space and time for many. In gist of it, no matter what the dealer understood and what limitation they have, there is a way to express that to a customer and that what gives me, a customer, a good or a bad feeling about the dealer.