I felt the same way the last couple years of his career when he kept being described as a sure-fire hall of famer. I guess 600 home runs goes a long way if you aren't Bonds or Sosa.
FWIW, he wasn't just a power guy; he also had a career OBP over .400, giving him a .956 OPS over 10,000 ABs. That ranks 18th all-time.
Nos. 15-20:
15. Joey Votto
16. Larry Walker
17. Johnny Mize
18. Thome
19. Todd Helton
20. Bagwell
Totally get the "he didn't feel like a HOFer," though. I think you could say that about each of the first five guys listed there (and some said it about Bagwell, though we know better after watching him every day.)