I can’t remember the last time I saw an ASL without a motorcycle, car, van or police car in it.
My beief is that most drivers, especially those who’ve been driving for many years, don’t realise they’re not supposed to enter the ASL.
I say this because I don’t remember ever seeing an ASL when I took my driving lessons & test back in 1991, or remember seeing it referred to in the Highway Code, therefore an ASL may be a relatively new phenomenon for a lot of drivers.
Around where I cycle I have noticed motorists increasingly stopping before the ASL rather than in it, so awareness does seem to be increasing.
Motorcyclists will probably always use them as it’s a handy space to use when they’ve filtered past traffic.