I guess there are multiple things going on and people often conflate them. I'm not a lawyer, but several friends are, so forgive me for paraphrasing a discussion between them and other friends of mine, I can't really remember their exact words.
There's a big difference between thoughtcrime and the fact that, at least currently, hate crimes would be criminal acts even if they weren't hate crimes. If you beat or kill someone, it's still a crime. The law is not asking to punish people for thinking of crimes. (Not mind you, that we're strangers to that either, just tell your friends you'd like to hurt the president, and you'll quickly find yourself dealing with treason, for example.)
Also, if you think that considering what people were thinking at the moment they've committed a crime is hard, you will be dismayed to find out that in criminal law intent is key in the majority of crimes. You get very different outcomes for identical acts depending on intention: if you drive off with my car planning to return it later, it's unauthorized use, not grand theft auto, even if you crash it an hour later and I never get it back. Another example? You are driving and talking on a cell phone with your friend, and you run over someone not knowing they are there, you're in for motor vehicle homicide… if instead you run over someone while telling your friend "Hey, here's so-and-so, I'm gonna run over them now", you're in for murder.
So yeah, harsh as it is, in the example Jeff offered, it seems that they *were* selecting someone to rob/assault *because* the person was gay, which the hate crime law was designed to be applied to. You may have noticed that when ordinary folks fall for a con artist we may ask "how can you be so dumb/greedy?" and give the con artist a light sentence, but when they scam old folks, the charges pile up quickly and people actually get up in arms if the law enforcement doesn't pile up the charges, everyone goes "that could be my parents you're talking about!" and just because we don't call it a "hate" crime doesn't mean that we don't apply the law more harshly when we perceive the criminals to be selecting people because they belong to some specific slice of the population.
Anyway, while we may acknowledge that some people are opposed to hate crime laws in general because they think it puts too much attention on motives over and above the criminal acts themselves, it might be interesting to also consider the fact that when an assault on an individual also functions to terrorize a community, it's not unreasonable to acknowledge those as two distinct criminal acts. Sometimes, as one of my friends said, it helps to treat systemic effects systematically.
Cheers
-- Paulo.
"The law, in its majestic equality, forbids rich and poor alike to sleep under bridges, to beg in the streets, and to steal their bread." -- Anatole France