I have not heard anything about Bachmann being in any sort of financial trouble, even with them sometimes struggling to get things out quickly. In fact from what I have heard Bachmann are doing absolutely fine.
Dapol seem to be doing ok, but have seen a drop in sales of 4mm wagons mainly due to the fact they look so dated these days. They are still getting new products to market, with the 68s being and various railcars being successful recently, and have a good number of models still in the pipeline. I think dropping the N gauge dummy units is a rational move, and is not a sign that they are in trouble. If the dummy units sold well, they would not be dropping them.
And then there are the other manufacturers who have entered the market recently, especially in 4mm. Rapido, DJ, Oxford, Hattons just to name some of the big ones. This is obviously going to have a knock on effect for the more established manufacturers out there. But if the hobby was unsustainable, would all these companies be taking such a risk in entering it now? I don't think so.
The Hornby situation says more about Hornby than it does the hobby as a whole. Obviously times are tougher for all hobbies and retail/manufacturing sectors, but well run and managed companies can weather these storms. Most of the model railway manufacturers seem able to do this, for some reason Hornby does not. It would be tragic if Hornby went bust, but ultimately I believe the hobby would survive.