I think Diet Rite was also a victim of the FDA's cyclamate ban.

Cyclamate + saccharin was like sucralose + aceK and aspartame + aceK... the pair synergized & tasted a lot better than either one individually.

When the FDA banned cyclamate, there was literally nothing BUT bitter-tasting saccharin to fall back on. DietRite went all-saccharin, but the new version was DISGUSTING.

TaB came out AFTER the cyclamate ban, so it was formulated from day one to be less-nasty with saccharin. DietRite, in contrast, risked an even bigger backlash if it changed any OTHER ingredients to try and improve the taste.

RC also pushed the myth that all-saccharin DietRite was "just as good" as the original formula, even though literally EVERYONE knew it wasn't.

When NutraSweet became available, Coca-Cola KNEW it was better, but pitched it as an all-new drink ("Diet Coke") instead of merely a better-tasting TaB (because, officially, there was nothing "wrong" with TaB's taste). Coke HAD to do it, though, because Diet Pepsi jumped on the NutraSweet bandwagon first, and was poised to SLAUGHTER TaB in blind taste tests (because Diet Pepsi w/NutraSweet WAS enormously better-tasting).

Trivia: "New Coke" was LITERALLY Diet Coke sweetened with HFCS instead of aspartame.

The explosive growth of NutraSweet-based diet drinks from PepsiCo & Coca-Cola was a big nail in RC's grocery-store coffin. Almost all the shelf space that USED to go to RC (and DietRite) was hijacked by new diet drinks from the other two.

I think RC also was slow to grasp the importance of NutraSweet in general. Remember, for 17 years, NutraSweet cost 2-4X as much per sugar-pound-equivalent as HFCS, and about 10-40X as much as saccharin. Diet beverages that used NutraSweet were LITERALLY loss-leaders until the last patent fell. RC took the short view & profitably sold small amounts of diet beverages instead of gaining market share while losing money on every bottle sold (the way Coke & Pepsi did). By the time the patents expired & RC embraced aspartame, their "diet soda" market share had fallen to almost nothing.

For ~15 years, PEPSI actually had a patent on AceK+Splenda/NutraSweet. It's why Coke was slow to embrace Splenda... without AceK to take the bitter edge off, Splenda tastes more like saccharin than aspartame. That's why you almost NEVER see sucralose/splenda used by itself in soda anymore. I'm not sure, but I think Pepsi STILL has a year or two left on its aceK+aspartame combo.