Common Courtesy has gone to the dogs..

So, I've been a bad dog mommy and hadn't taken Maggie to the park lately. Since I actually managed to finish my homework on time (early even!) we went to the little dog park about 3 blocks from our house.  We were there less than 15 minutes.... 
No sooner did we get to the park did a large (poodle? grey labradoodle if that's possible?) start taking an interest in my little 11lb baby.  It sniffed her and followed her around and after about 10 minutes, it just didn't get the message that Maggie wasn't interested. 
He(?) tried to hump Maggie, but was way too tall so it just stood over her, which seemed pretty creepy!  She kept trying to get away from him and trying to put me between her and this behemoth. This went on for another couple of minutes and Maggie finally gave him a warning snap, which was presently ignored.  She decided she had enough and tried to jump up to my arms so I picked her up and carried her to the other side of the park; Big Grey followed...  Let her down for a minute and Big Grey started up again and so we just left.  This whole time BG's owner was standing there talking about how cute it was and how her dog is just fascinated with little dogs and even after I carried Maggie away she never once called her dog off, despite Maggie's distress.  Even Maggie's snap didn't clue this woman in that she needed to corral her dog- although I do believe that dogs need to sort things out like that and you can't go jumping in every time there's a snap or scuffle.  But after my dog snapped and her dog completely ignored it, she should have done something besides just giggle over the little dog giving some attitude to the big dog.  Or maybe I'm off base?
I don't care if our dogs play or if your dog humps mine or whatever the case happens to be.  But the moment I see your dog looks even the slightest bit uncomfortable or isn't interested, I make Maggie "leave it!".  The last thing I want is for you to feel like you and your dog can't enjoy the park because my dog is an ass (which she sometimes is).  I will leave with my asshole dog if that's the case because you are there to spend time with your dog and socialize with other dogs and get some exercise or whatever it is you are there for.  Yes, I believe dogs will be dogs and that they need to sort out their own issues, dog to dog.  But come on...