Quite agree, maz.
The argument is almost the same.
The difference is the bus service is provided for [HI]people[/HI], not dogs, and the OP was about banning dogs from buses, not old men (not women?) with dubious hygiene.
Referring to my earlier post...
would you object to my pet, a pot bellied pig, sharing your double seat?
After all, I would pay for his ticket, he is well behaved, I always pick his crap up and he understands every word I say.
But 'people' includes 'people with dogs'. Dogs have always been companion animals - unlike pot-bellied pigs, which I seem to recall were something of a fad from the eighties.
'At the driver's discretion' should be good enough - without the need for knee-jerk bans to pander to the more intolerant among us.
If your pot-bellied pig was to be allowed on the bus by the driver, fair enough - although somehow I doubt that it would be. 'Driver's discretion' = common sense, which seems to be constantly under threat nowadays.