Just respond with "Yes, but what about useful aspie obsessions?"
Some are just hobbies and stuff... now - a useless obsession is mental distress with intrusive thoughts. Those are nasty. That's a useless obsession right there.
An obsession that's really no one elses business is performing perhaps slightly unusual routines within a day... that can be useful for the aspie - if it helps them to feel satisfied.
Useful obsessions would be over obsessing on your favorite subject perhaps... be it maths, music, or whatever.
Something like that...
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Thousands of candles can be lit from a single candle,
and the life of the candle will not be shortened.
Happiness never decreases by being shared.