History will repeat itself. Lionel only cares about selling thousand dollar locomotives to O-Scale enthusiasts, and leaves the O-gauge enthusiasts to pick up the bits and pieces online.
I'm not convinced we can pin those decisions on Lionel not caring. Perhaps they and others are just meeting what the market demands. I'm a semi-scaler with no plans to ever get into full 1:48 scale unless we move to a home with a bigger basement, and I'm hoping to avoid both of those expenses. Yes, I agree the catalogs seem better for scale operators than semi-scale operators, but I think that's the nature of the market.
I've picked up numerous engines and rolling stock from guys selling off their semi-scale gear in a move to scale. That tells me I'm in a minority as a PW-size guy. I picked up gobs of O27 tubular track the same way. I don't think there are any going the other way, from scale to semi-scale. My sense is there's a good number of retired boomers in good shape with pensions and 401ks who don't mind dropping $1-$2k on an engine. Lionel would be crazy not to serve them if they can make a good buck doing it. No different that GM and Ford getting out of the Cruze and Fusion to focus on higher margin SUVs and trucks.
On the other end, while the Scooby-Doo, North Pole, Frozen, and Toy Story sets aren't for me, all indications are that they sell by the truckload to entry-level and Christmas-only buyers.
That leaves us semi-scale, PW-sized guys in the middle and an upside-down bell curve. We're the minority. I discovered Rail King locomotives too late, but believe this is where MTH was superior in offerings to Lionel. Unfortunately, Rail King's future is in doubt and, perhaps, that's because it's a great product line chasing too few buyers.
My strong guess is that we'll see few, if any, new semi-scale locomotive molds built in the future. There are so many out there that can be retrofitted with modern electronics for half the price of a new one. With few of us in the semi-scale space, that may be our best option if we want something not on 1-3 pages of each year's catalog.