I have a recipe for you to taste. It has three ingredients:
A) Providing support for a game can be an onerous task for a company. It takes a lot of man-hours to manage forums, answer queries, provide new content, etc. Whilst marketing and sales efforts have an obvious return in the form of increased revenue, aftercare does not. Sure, if your customers like you more then they’ll be more likely to recommend you and buy future products, though this is unlikely to demonstrably make up for the cost in wages alone to provide this support.
B) Most game companies are small, with only one or two lines. They can focus on, and provide support for, a small area as this is all they do. Larger companies with many games have to dissipate their efforts to support them all.
C) Board games require less support than figure games, simply because board games are more self-contained. This generally makes them easier to playtest and less woolly in the released version, so there are fewer game issues. While enthusiasts may want more scenarios, expansions and so on for board games, many never expand beyond the initial offering. Tabletop figure games, on the other hand, are generally open-ended. Therefore, while large companies with many board games can provide acceptable support for most of them, those with many tabletop games may struggle.
if the above is true, then GW’s lack of support for its Specialist Games makes perfect sense. In fact, the costs to suport them would far outweigh the revenue doing so would generate and therefore would be financial idiocy.