The difference Hooves, which has already been pointed out, is the risk to others and drain on already overwhelmed emergency services.
As I said, France has really tough lockdown rules which they've had to relax for people with Autism BECAUSE of the number of incidents of extreme violence necessitating emergency services including FIRE FIGHTERS in some cases, presumably to use hoses to subdue when Police have been unable to.
In a pandemic, Governments don't give a shit if anyone Autistic or not, harms themselves quietly or if anyone needs more meds or physio or respite or is struggling and needing help.
What they DO give a shit about is when large numbers of emergency services staff are tied up trying to subdue an Autistic person in a violent episode and then possibly going off sick due to injury or trauma.
They then have to find somewhere for that person to be placed. They can't just calm down and be sent home because it'll happen again if it's a reaction to not being able to go out for their usual walk or whatever else disruption caused the violent event.
So they have to go to a secure unit, prison (depending on who they assaulted), hospital etc. Which is a further drain on resources.
So it makes sense to say they can be taken out for a drive or go for a long walk or to their local park if that's going to avoid the above.
It's not Governments being kind or saying some people are 'special' and some not. Nor do they probably care that much about the Autistic person themselves. It's protecting their resources and saving money. Which is now more important than ever.