In honesty, most of them are just furfriends in denial. I never stated all were autists, but it's like feminists. Not all are horrible people, but most are.
And this is based on interaction or lack there of on the Internet?
The Internet is like giving a bunch of people megaphones. The actually normal people won't use them to try an communicate with others close by but, the obnoxious ones will use them in an attempt to gain attention thus drowning out the normal ones and making them inaudible.
How many bronies have you had an actual conversation with irl?