I'll step up and offer some defense for the musicianship of James, Kirk and Lars.
James is a very good rhythm guitarist. One thing you ought to keep in mind is that James is one of the legitimate inventors of thrash metal. Sure, many others have since surpassed him (Jon Schaffer is a great example). But it takes a fair bit of skill (especially right-hand skill) to play some of his parts. He's no virtuoso, but he's no slouch either.
Kirk tends to rest on his laurels sometimes, but he has created some monstrous classic solos. He's not consistent, but when he's on top of his game he is indeed world-class.
Lars, in his younger days, was a hell of a drummer. I think he hit his peak around Master Of Puppets. Check out some boots from that tour; you'll see how great he once was, and how far he has fallen. But I really liked his drumming on the latest album. What he lacks in skill, he has finally made up for in taste. Yes, he's an intolerable dumbass, but he's still a good drummer. Not great, but good.
Are they "average"? No. In my opinion, they are all well above average, yet not superb (with the occasional exception of Kirk).
More about the speeches...
When James listed all those bands who aren't in the Hall, I was shocked to hear him say Deep Purple. I thought they were in. There's no question they deserve it. As to the others... I set the bar high. I wouldn't put Thin Lizzy, Judas Priest or Motorhead in the Hall. But Maiden and Rush are also unquestionably deserving.
And I was happy to hear Trujillo mention Suicidal Tendencies. Again not Hall material there, but they were a great band. ALL I WANTED WAS A PEPSI!