The they are all horrible names. I'd like a return to Eldorado, De Ville, Fleetwood, etc...
However, apparently alphanumeric is big in China, and that's the market to swoon to.
It's not necessarily that it's "big in China", it's just easier for international companies than dealing with coming up with names that aren't filthy words in any of the countries in which you hope to sell your cars. You can just use the same name and badges everywhere in the world.
CEO Johan de Nysschen is on the record at
his Q&A session on Jalopnik and in
a response to the AutoNews editor that the historical names are largely only meaningful to baby boomers in the US and have no draw in the international market Cadillac is trying to expand into. It's easier just to give the cars alphanumerics that immediately tell you where it falls on the hierarchy and build the Cadillac name as a whole rather than an individual car's (Escalade excluded), and I see his point.
Consider: Cadillac is trying to match Buick in China, and make inroads into Europe. To those audiences, there is no emotional attachment to names like De Ville, Eldorado, Fleetwood, etc; they never got them, and so there's no name legacy they can use in marketing and drawing people into the showrooms.
Keeping in mind too that new luxury cars appeal to image, a clear hierarchy with alphanumerics instantly communicates where a purchaser falls on the spectrum of purchase price and therefore perceived success. The Chinese man who made his fortune and is now looking for a ride has no clear idea whether the Eldorado he's considering is pricier or better than his boss' Fleetwood, but he does know his CT4 is below his boss' CT6. It'll also build Cadillac's image if successful people buy them, as few people in such circles answer the question "What do you drive?" with "I drive a CT6," but rather with "I drive a Cadillac." Think of how many times you've heard a BMW or Mercedes driver say that, even if they're only leasing a no-options C-class or 3 series.
Now, you might be asking why they at least don't keep the historic names for the US? De Nysschen says their research indicates they mostly resonate with baby boomers, the youngest of which is already looking at retirement. They're done, and out of Cadillac's target; the brand is going after the rising and just-apexed businessmen who grew up after Cadillac's heyday.
Assuming this is the replacement for the XRS?
SRX. I heard a rumor somewhere that it's actually built on the bones of the SRX since the new platform wasn't ready in time, but all other information points to all-new.