What does Mr. Antolini see in Holden’s future? Additionally, what does he say about the “environment” in which Holden lives?

Mr. Antolini sees Holden as moving toward a terrible fall. He tells Holden he sees him putting himself in danger for an unworthy cause.... of losing his life for nothing.

"All right. Listen to me a minute now . . . I may not word this as memorably as I'd like to, but I'll write you a letter about it in a day or two. Then you can get it all straight. But listen now, anyway." He started concentrating again. Then he said, "This fall I think you're riding for--it's a special kind of fall, a horrible kind. The man falling isn't permitted to feel or hear himself hit bottom. He just keeps falling and falling. The whole arrangement's designed for men who, at some time or other in their lives, were looking for something their own environment couldn't supply them with. Or they thought their own environment couldn't supply them with. So they gave up looking. They gave it up before they ever really even got started. You follow me?"