OK, so I have been reading posts here for a long time ('lurking' as they say!) because, as an EI speech therapist, I want to be in touch with how parents of my special needs kids think, feel... All of you on this site have been very helpful to me professionally. This is the first time I felt such a strong need to respond to a post!
First of all, it is normal for a 2 1/2 year old to leave the final sound off of words. Not all toddlers do this but it usually goes away around age 3 years 3 months. Up until then, it is considered normal. Could it be a sign of something else (hearing loss, apraxia...)? Yes. But in and of itself, it is normal.
Articulation therapy for a toddler is not based on sitting still. It is play-based, fun and engaging! As a PP mentioned, Dr. James MacDonald is a great resource for appropriate EI speech therapy. You definitely can request another therapist or at least challenge her to explain why her expectations are so high for a 2 year old!
And a Behavior Specialist? Hummm...
3years 3 months??? Really? After listening to him interact with the developmental specialist for about 5 minutes, the speech therapist told me "this is a problem that does not self correct." So I am surprised to hear another speech therapist say this. His articulation has been getting better and better, I think, but slowly. I am in the process of scheduling a hearing test...
I think the therapist tried to be playful with him, but I think her focus on positioning him wore him down and overshadowed the articulation exercises they were working on. As I mentioned, by the end of the session he had shut down and was curled in my lap sucking on my shirt. He was quiet and withdrawn for over an hour after she left.