That's because you're taking it as literally as possible to where it's offensive regardless of context. Context matters more than the word itself. Also, people are more than able to disassociate a word from its original meaning to mean something else. Take your use of homophobe as an example of that. 😽

1. These words are offensive/hateful by your definition.  And that's the problem with "hateful/offensive" words.  Every person is offended by different things.  Really any words can be derogatory depending on how you use them.  And quite a few people are just out to find the next offensive thing for the sake of virtue signalling.  Just like how actual medical classifications slowly become "offensive," so they must be changed.  As someone posted earlier, this is how the classification was changed to retard, as the ones used before were "offensive," and then changed to mentally disabled.  And I bet before I die, that will be deemed offensive and changed, yet again.  Crippled was changed to physically handicapped, and we are already seeing some people being offended by that.  It's just pathetic really.

2.  Because people are not equating a group of people.  They aren't insulting truly autistic people, or gays, when they use those terms.  Language is fluid.  It's the reason people use homophobe, even though that word should describe someone who is actually afraid of a gay person, not someone who dislikes them.  Of course, that word, as well as racist and misogynist, are thrown around so loosely, they have almost lost all meaning.  Anyway, gay meant happy at first.  Then, the gay community took that word to describe themselves.  Well, straight people just took it back, making it mean bad/lame.  It's not an insult to gay people, it's just being used in a different way.  If gay people don't like it, they can either get over it, or find another word.

Because essentially they are similar, people don't choose whether they have autism in the same way that people don't choose their race, so criticizing/attacking them for it should not be acceptable. Using autistic or "dripping with autism" as an insult is saying that being autistic itself is a bad thing.

That's like telling a gay person that he is dripping with gayness or homosexuality, people can have the freedom to do that offcourse and im a defender of freedom of speech but it makes you sound like a childish douchebag and it does not help to do that in conversations and surely not if you want them to open up.

BTW the OP just asked everyone to be nicer, thats not much to ask its not like he wants to restrict freedoms.

Except no, you're conflating known symptoms of a mental condition to gay people. Read my previous post to VGP.

And most of my irl gay friends would be ecstatic to be described as "dripping with gayness".

The symptoms have a very widespread variety and most that call others autistic doesn't even know what the hell they're are.

Hey nothing wrong with friends joking at eachother but this is about having some decency against the ones that aren't you're friends.

They aren't similar. One is a race of people with individual thoughts, freedoms, and personalities. The other is a mental condition that affect the individual thoughts, freedoms, and personalities of those who have it. We're not talking about stereotypes, we're talking about known symptoms of a known condition. Comparing black people to autism is tantamount to claiming black people have little-to-no control over their actions, which is also a perfect example of the "soft bigotry of low expectations".

And we're very clearly discussing one set of symptoms of one type of autism.

The problem is when you are using those words to insult someone.  "This thread is gay" = not okay.