You know, things change, markets change, people's desires change, and opinions change. I agree leaving the market means you have to start from scratch next time, but if your choices are continue spending money in a shrinking market where profits are thin, or invest your money into a market where you have definite strengths and the profits are much better, which do you do? You forget that Ford doesn't have unlimited resources to engineer and plants to build vehicles. You sometimes have to make tough choices to cut something in order to succeed.
So, let's say Ford chose to cancel the Ranger in order to bring the Transit over here due to resources. Was cancelling the Ranger a bad move at that time? Sales were down and profits were nill and it was going to cost a fortune to update the T6 to bring it here. Ford saw the opening in the van market because nobody had anything else, and Ford KNOWS the fleet market. Fast forward to today. Ford makes a bunch of those vans, in a shared plant with F150, using shared powertrains and economies of scale. That was the right move at the time. It sucked to lose Ranger, but it was a necessary move to make Ford viable. Sure, Ford is a bit behind in the small truck market, but in the end, they are more than making up for it with van sales. It will take them a while to get the Ranger back to the top, but with Ford's truck dominance, I feel they will get there.
And Toyota dumping the Camry or Honda the Civic is entirely different. That is their bread and butter. That's where they put their resources because that's what they know. Do they know trucks? The Tundra and Ridgeline show they don't, at least not here in the US. In the end though, if sales continue their downward spiral for cars, look for them to be cancelled. I don't think it will go that far, though, because there is a certain number of sedan buyers, and they will all migrate to the few that remain, and those will be the stalwarts, those whose bread and butter is sedans.