Does this type of depiction really advance understanding of disabled individuals?

The television show Glee features a character with a spinal cord injury. There has been discussion, here on Fluther and in other arenas about the fact that he is played by an able bodied actor. Tonight’s episode featured another disabled character – played by an actor who is quadriplegic. I tuned in, only to see this character’s one and only scene take place entirely with him in bed. Not only is the character portrayed as completely immobile, he tells a story of how when he got a power chair he could move himself, he drove it into a pool with the intent of drowning himself. I found myself incensed after watching. Any thoughts on this type of portrayal of a disability? Might this actually be worse than an able bodied actor portraying a disabled character?