As someone who's spent a good quarter of his life in France, it's all too clear to me the damage that can be done to the hobby when a major manufacturer stops supplying retailers with stock. In Lima/Jouef's case it was down to bankruptcy rather than greed / business choice, but the model shops stopped receiving stock almost overnight and that was that. A year on many of them had closed down and made way for other small businesses. At the time there were no other major manufacturers producing French-outline stock in H0 scale, and N was never popular over here (and still isn't - I have yet to meet anyone who models in it although it's present at shows etc). No stock = no more sales. No sales = no more shops. No shops = no new customers. The casual hobbyists and collectors inevitably moved onto railway simulators / flight simulators / other hobbies due to lack of available stock. And of course when things did get going again with new manufacturers appearing and Hornby's slow revival of Jouef, fewer customers meant less demand, so higher prices, so less demand, so higher prices, etc ad infinitum.
There are now just a handful of railway-focused model shops across the country outside of Paris*, and those that have survived had to diversify by making plastic kits, model cars and R/C boats / aircraft / land vehicles their main business. Apart from a couple of "rail emporium" style shops in Paris*, the stock of railway models that can still be found in the remaining retailers I've been to since I moved back here in 2012 is extremely limited and very highly-priced. My latest giggle was a 250€ / £180 price tag for a "rame reversible" - i.e. two coaches and an unpowered driving van. That's £60 per coach, or double the price of a modern, high-standard Mk1.
In my experience the French have always had far less interest in the railways (model or otherwise) than the British, but most of my (male) friends still had train sets when I was in France in my early teenage years. Now the hobby is essentially dead to anyone but the serious modeller, and in my day-to-day life here since coming back I've never met anyone in their late 20s / early 30s who has an interest in model railways, in fact they've never even seen N scale trains and are fascinated by the size of my "tiny British trains" when I get deliveries at work.
It would be a great shame for Hornby to make a deliberate move to withdraw their stock from retailers' shelves. Due to the presence of other manufacturers the market would probably survive better, at least in the short term, than it did in France, but not in the long term as this will kill off "new blood". Let's face it - how many railway-oblivious parents go into shops looking to buy a Bachmann train set for their child?
I'd be very worried for the hobby if Hornby decided it didn't need to have its products on shelves, and I'd be rather worried for Hornby itself as I think they're being a bit naive if they expect the clueless parent to spend £150 in their online shop on a product they can't see / feel / look at before committing to it, when for the same price they can go into their local GAME or HMV and have a demonstration / play of the latest handheld games console.
* Paris has a completely different market. Anyone who has the money to a) rent / buy a place in Paris with enough spare space for a H0 model railway and b) also actually spend money on model trains on top of that is definitely not in a position where they need to keep an eye on spending as most of us find ourselves doing.