Here's a few possibilities as to why:
1) There aren't as many models to talk about
2) They aren't as popular due to price or shiny tracks
3) They don't produce 20+ models every quarter
4) They have a larger scale
5) Many people are Philistines
6) Mostly German themed - only 3 Shermans for you disturbed, Yank-Tank lovers
Feel free to add anything I may have forgotten!