Cliff Notes version: Technology has stripped Ti's cachet, but hasn't lowered its cost or the difficulty of working it.
For the bored:
Ti has a limited appeal. Always has. Now the Ti crowd has the CF option, some good Al options, and even some custom steel ... there just isn't enough of a market to justify the material for most manufacturers.
The "steel is real" crowd is more numerous and therefore a better target market.
Ti used to be the summit, the "best" frame material ... lighter than steel, with a better ride ... but advances in Al have made that advantage meaningless, and CF has become the "Best" frame material for most, because it is what the pros ride.
Ti is heavier than CF and a lot harder to build correctly. Ti is expensive as a raw material. Ti offers only marginal benefits over the competitor materials---more durable than CF (but people buying CF aren't looking for that, primarily; people looking for longevity buy steel) and lighter than steel (but people wanting "light" are buying CF.)
People who want fast bikes buy CF. People who want comfortable bikes buy steel. So ... people who want expensive bikes buy Ti? No .. . they buy custom steel or high-end CF.
Ritchey sells bikes for money. He can make a lot more money selling steel to more people than Ti to fewer ... it has nothing to do with which material is "better" ... except in the limited realm of "commercially better."
I'd love to buy Ti as my "rest of my life comfort ride"---braze-ons for full racks, wide enough to accept touring tires, fender mounts, and extra bottle mount on the downtube, maybe .... endurance geometry .... but the cost for a butted-tubing Ti frame is really hard to justify when I could get the same thing in steel for much less---and likely the two frames would both be exceedingly comfortable anyway.
The number of cyclists with the cash to buy whatever they want, and also the desire to buy Ti, is small and shrinking. The cost of custom steel will always be lower, and as the market shrinks, the price disparity will likely grow. For a small manufacturer, where it is harder to amortize costs over a smaller production run, it only makes sense to drop the narrow-margin items.