As someone's been studying this, and working with the population for many years, there are definitely two sides to this.
Autism is very real. I have my own personal beliefs about why it's become an explosive epidemic in the past 20 years, but that's just my own opinion.
Over-diagnosing and recklessly diagnosing autism is also a problem. It was sort of the first big "trend" in seeing how rapidly and uncontrollably people, and the medical community, were jumping on a medical diagnosis bandwagon. Kids who simply had ordinary behavioral issues were slapped with the label because it was trendy, and it was lucrative. People were going online and taking "self diagnosing" tests and then proclaiming themselves "on the spectrum" so they could feel special and get attention and join the hordes of online support groups. So, this very real disorder has been somewhat hijacked, and that's damaged the reputability of the whole thing.
That said, I'm not going to tell anyone that they aren't or couldn't be on the autism spectrum. If someone has genuine, documented struggles with socializing, communicating, neurological, or sensory issues, I think they should seek out a reputable, established, trustworthy professional, and find out more.