Operative word being "if".
Did you actually read my argument. I literally said if they're going to fix it, they should. If they aren't—which they haven't done in six years—remove it because the current implementation renders it useless. It doesn't matter what purpose it could fulfill or how useful it could be. If they aren't going to change it, then abilities like Piercing Talon are button bloat because they serve no functionality. Comparing to Leg Sweep only epitomizes that. CC abilities are generally useless in this game outside Eureka—to the point I'd wager very few people bother with them. You keep arguing in a "could be" scenario.
It isn't a slippery slope fallacy to posit combo consolidation will result in less skill pruning. Or that they aren't add enough abilities to compensate for it. The entire purpose of such a change is so they wouldn't have to make any others. And it's the primary concern many people have with the feature even being optional. It removes any incentive. After all, if DRG went suddenly had six extra slots. What reason to the devs have to remove other abilities that aren't useful? Likewise, they aren't going to add a slew of new abilities or it defeats the point of removing any to begin with outside of a new flashy animation. You go on to mention abilities that are almost all oGCDs and/or you typically press sparingly. Defiance/Deliverance for example is two buttons you'll virtually never touch except during your opener. These aren't the same as a combo which you'll spend the vast majority of your time executing. Hence why there is much more pushback about combo consolidation than making Shield/Sword function like Grit.
As for PT and gameplay. I hardly call it compelling gameplay to use a garbage range attack on a melee DPS even if they did make it so your combo wouldn't break.
Nonetheless, we'll have to disagree on that because you seem to find it more interesting than I do.