Well that's a shame. I believe it makes more sense to perfect the stable than re-tool etc for obsolescence. Don't know why I have such an affinity with the .17 Rem. Still confused why they didn't tweak it and become a major competitor to the HMR: Reload capable, reduced charges, increased charges, better bullets...
HMR succeeded by NOT being a reloadable cartridge. $8.99-$12.99/box of 50 upon launch = "Why would I Reload?" as well as significantly quieter.
From a pure FPS/noise standpoint, the .17 Hornet could've been "That Competitor" to the HMR but the cost for ammo was ~2X the HMR, the magazine only held 6, the rifles so chambered were significantly more expensive as well as far fewer choices, and if hand loading, 17's in all iterations are a pain in the rear, it's easy to fold over a neck if you're not slow and careful getting a bullet seated and you need a new flimsy cleaning rod as well as patches that don't work for anything else. Loading .17's requires the patience of Job.
.224 cases, projectiles, barrels, twist rates, and multitude of rifle choices are what they are because there's so many of them from the factory. .22 Hornet, .218 Bee, .219 Zipper, 220 Swift, 220 Rocket, .221 Fireball, 222Rem, 222 mag, 223Rem, 224 Weatherby, 22-250Rem all in multiple rifles from multiple manufacturers. Toss in another dozen + wildcats and it's easy to see why .224's outpace the sales of everything narrower than they are.
In CFR .172 land you've got Remington, Ruger, Marlin/Savage, and Sako and that's about it.