I think depending on the special needs, then yes, T's should make allowances. Obviously, any physical special needs (disabilities, etc)., T should accommodate to the best of their ability, or ensure the client is referred to someone suitable if T cannot accommodate.

If we are talking about mental and psychological special needs, then that falls within the realm of T's expertise, experience, and judgment if they can sufficiently treat and help the person.

As for the comparison to rocket science, I get it completely. Rocket science is logical, rational, tangible. You can see it, it's 1+1=2, it can be learned from textbooks, lectures, etc.

Being a client in psychotherapy is definitely not something that can be learned from textbooks, or has any of the characteristics of learning rocket science. Being a client requires much more freedom, incorporating feelings, emotion, abstract thoughts. There's no specific way a textbook can tell a client "analyze yourself this way" because that would be different for every person.

Hankster, that's a great comparison, thanks for sharing it!