Subsidised school buses due to parental choice is a definite no from me. You do need to own your choices. The comment about after school clubs is completely tone deaf.
Perosnally I don’t even think children should receive free transportation to special schools if they are already receiving PIP/DLA because the state should help subsidise the extra costs of their education and attendance, they should only have to pay for it once, not twice.
For a disabled child DLA often doesn't touch the sides. Adaptations to the home, therapies, special equipment and clothing, special foods - it is so expensive. Both parents usually cannot work full time.
There is NO WAY it would also cover the cost of a specially adapted taxi - and escort, many kids can't be safely put in a taxi without a 121 due to needing airways suctioned, risk of eloping etc - to schools which can be 30, 40 miles away. It cannot be compared to electing to send a child to a 'better' school. If there are less seriously disabled kids who "get a free taxi" around the edges of the rules or on a technicality then it's better than leaving the most vulnerable with no means to access education at all.
Campaign for better local provision or satellite special school "hubs" in towns and village if you must.