That shell remain one of the great examples of unexpected casting. I simply loved every moment Ryan was on the screen - he fit so darn perfectly in the overall picture.
I believe part of EWS downfall was in Kubrick's desire to repeat that successful trick. Take a shit actor, and build such a structure around him that he positively shocks everyone.
Perhaps Tom was not the right person for that trick, but it failed there miserably.
Perhaps O'Neal's succeeded simply because he didn't think of himself as of a super-star, and let the director use him as a master would use his brush.
