While it can already be a good quick-play spell on its own, the added flexibility of being able to target your own monsters can be useful, especially since cards like Wall of Disruption, field spell, or attack increase cards are used somewhat commonly. Using Gravity Lash and Reverse Trap can catch your opponent by surprise and win the duel early.
That's why the word slower is in the post second "where people play good decks", this doesn't necessarily mean that these decks have monsters with high Def and everything will drop below 1000 Atk but it's still a good card that will see some play yet it won't reach the level of econ, MW, WoD, SRH or FTH
when you think about all the advantages of a quick play, tbh its better to run in most deck. course nothing beats the versatility of e-con. but with gravity lash you can defend yourself from a storm play play around ama go aggressive, you're not dependant on your opponent attacking etc ...
also while it doesn't see much play the delay will make people think its an e-con and they be like so worst that can happen is my monster is switched to def and then attack to get rid of it but then you hit them with this and that could be the win right there.
also look at the monsters when hit by it : rez:400 gozuki:900 skull:1700 whyvern:200 a.overlord:600 a.telepath:600 a.warrior:800 flying fish:700 shark:200 oyster:200 hermatree:900 dakini:300 saffira:100 black.b: 700 salamandra:950 hydro:600 valkyrion:0 dangereus:0 slash dragon:400 abyss:300 etc .. the onlt monsters i can think of that beat it are glads gaia and cidatel(cuz of effect)
I dont understand why no one look at this card, i think its very good for generic backrow