I was diagnosed with Asperger's. Nowadays, I say I'm autistic. I don't see how this wouldn't skew the perception of people who know me to think that autism is a more mild condition than it used to be.
I disagreed about the part that the DSM 5 is to blame.
If you were diagnosed with one thing but decide to tell people you're diagnosed with something else, that difference doesn't appear to come from the DSM.
Asbergers is not a thing anymore. It has been folded into autism, which is now a broader diagnosis than it once was.
I'm sure the powers that be had a reason to combine them; and I am no where near qualified to have an opinion on if it was good idea or not. But expanding the definition of autism to include milder forms was 100% a choice that was made.
The fact that the public perception subsequently shifted to view autism as less severely disease seems to me to likely be causally related.