I remember hearing Tablets are the other blemish wheels and they just machine down the outside. If that's the case they should stay since they're cutting down on waste.
Frankly I can't see why Conical shapes need to exist. In what scenario is a sharply angled edge profile better than rounded? Ditch those and just have Classics, Radial Slims, Radial Fulls, maybe one other novelty shape.
Yeah there's reasons. It changes how the wheel does certain things.
They're more "stable". They are harder to make tip/tilt, and there is a more binary (definitive yes or no) when they do tip. This makes them very "predictable" when skating.
That stable flatness also makes them better for power-sliding IMO. You can really dig in your heels at speed and not worry about tipping on that radial edge.
They also lock-in more securely, which also gives them more "predictability" in that regard too.
They also do flip tricks differently. I would argue they flip worse (again, more stable) but some people like how they flip more than rounded. While more rounded/teardrop wheels have a smooth easy flip, conical wheels have a bit more of a delayed "snapped" flip off of that more "binary" edge.
On top of all of this, if they are cut deep enough, they are more lightweight than rounded wheels. Conical wheels are typically more cut out on the sides, while radial wheels tend to have more convex volume outside of the ride surface (hence higher weight:width ratio).
They're definitely worse in other ways... but overall I feel more in my comfort zone with conical wheels. I feel more in control and confident due to the above differences.