Can you blaim them? BT sells models.
That might be true for resellers but it certainly doesn't seem the case for Geedub these days; I can't remember the last time I saw a BT character/upgrade sprue in-stores, and Forgeworld has been gradually removing their BT products for a while now on account of them not selling particularly well.
That's assuming people actually buy them from Geedub, though.
Do you have a source for that claim?
I would actually bet you that the contrary is the case. BT seem to be one of the most popular (if not THE most popular) second founding chapters, judging from the general community activity (recent twiter survey for example).
I guess the recent phasing out of various chapter unique models, accessories etc. (not just BT) has mainly two reasons:
1. focusing on one chapter (posterboys) is more economical
2. freeing production capacity for new products
i think it is like Henricus told that. In 5th Edition, i saw many guys playing Black Templars,... nowadays not. There are far more DA, BA, SW, Ultramarine-Players in stores. But I also think that the rules leads to that. The specialedition Codex 6th Edition where was at first selled out ---> CF/BT