I've had experience on both end of the spectrum dealing with straight guys. Choosing to focus on the good experiences because focusing on the bad never helped anything.
I can see where some gay guys can be pretty aggressive approaching a straight guy. And it's hard not to expect the straight guy to be equally aggressive to get the guy to stop. I think the thing is, there is a respectful way to show your appreciation of a hot straight guy. I remember a conversation with a straight guy I indirectly hit on. There's a pretty trendy area in Baltimore...well...three now, but back then only really one. I saw the dude by himself and he looked like he was waiting for his close up for the A&F catalog. But, being a frajock at the time, it bothered me to see him flying solo. So, I wandered over saw what he was drinking and bought his beer and myself one. Plopped on the barstool next to him and offered him the beer, simply saying, "A hot guy like yourself shouldn't be alone. I think there is a law against it or something". It was a risk, but it wasn't inappropriate and I happened to gauge the situation correctly...he was out alone because of some personal issues. He seemed appreciative and while there was the urge to try something, I learned from being fratjock type to just appreciate what I did get. Don't talk to him much these days, but I still get an email from him once in a while.
So, it is possible to approach you straight guys, just have to do it correctly. Sometimes all you're going to get as a gay guy from a straight guy is a new buddy and that's not a bad thing.