Virtually no one claims that ground effects have "no business in D&D", most of us are quite aware that D&D has a lot of ground based spells like Spike Growth, Grease, Web, etc. as well as items such as Alchemist's Fire or oil/acid flasks. What D&D DOESN'T have are cantrips that deal damage AND create a surface effect in addition or even on a miss. Of course throwing an oil flask with your rogue and having your mage set it ablaze with Burning Hands or even a Firebolt should remain, no one is arguing that. But a Firebolt that creates a fire ground effect by itself is a bit much, not to mention the general overuse of such effects.