I used to. Quite a few rounds of limerence for me- obsessive crushes on people. I'm what I expect you would term 'pathetic' or- at least, I was. I can see it all for what it was now though and fortunately, I haven't fallen in that trap recently.
I do understand what you mean by the way. I'm not exactly calling you out for judging some people to be 'pathetic'. I'd like to say though, that it isn't exactly someone's fault for becoming fairytale obsessive like that. They may even realise themselves that it's kind of a foolish and extreme reaction. When you're caught up in it though, it can be hard to see the wood for the trees. Plenty of people will be only too happy to share their opinion but, that doesn't always help. In fact- if they tell you you're being immature or air headed about it, it may only intensify your feelings. No one likes being told their feelings aren't real.
I'm not meaning to have a go at you. I don't think you were really taking the piss out of these 'pathetic' people. Still, a friend of mine used to lightly tease me over stupid stuff I'd done and it did kind of hurt. I think because, on a certain level, we realise it's delussional. Especially if we feel embarassed because we know we have no real chance with them. Still- the feelings are still there none the less and they are terribly intense. Seeing as we are lead to believe that love is terribly intense too- how are we to know the difference?
I believe that limerence is a real phenomenon and it sometimes develops after people have been neglected somewhat in childhood. So, while it probably looks 'pathetic' to the outside world, I'd argue that it's actually more tragic. Kind of why people fall for romance scammers- they're simply desperately in need of love and they project what they need on that person I suppose.
Thankfully for me, it all passed over time. I looked up 'obsessive crush', found the term 'limerence' and have managed to control my crazy obsessive side since. I kind of know it was limerence too because one of the guys I liked I know is dead now and I don't feel very much at all. That would be weird if I had genuinely loved him. But yeah sure- at the time, I would have done almost anything for them to love me back.
I am sorry for your situation though. I have a friend who loves a rather mixed up, unreliable guy. Her friends and family low key hate him for how much he's messed her about and hurt her but I think she still loves him. We can't exactly choose who we fall for.