He is a giant in the industry and one of the alltime greats, & I cut him a lot of slack too. That being said, he has crossed well into self parody - and that can't ever be good!
On a related note, I went to a presentation by Billy May (robot in Lost in Space, among other roles) back at a Chiller Convention in 2000 or so. He was booked for about 25 minutes but no joke they couldn't get him to shut up and off the stage. He kept talking and talking for about 90 minutes, backing up the whole program.
No bitterness or anything: just another short guy who just talks and talks and talks... ;-)
His movie career spanned nine decades. I think he's alone in that group.