The difference between Enochian and old Greased Lightning is that Enochian actually had a means of recovering it if it fell off, without tradeoffs and on a short cooldown. The only time Monk had something close to that was Stormblood and the devs didn't like that we were Tornado Kicking so they killed Monk's recovery instead of changing Tornado Kick. The solution has always been simple, make GL recovery good and relegated to one action, clean up our upkeep actions so we only had one, change Tornado Kick to something else, and give us some reward for very basic upkeep or something else to strive for.
As for why people would consider nuking GL a good start, I'd say there's a couple of reasons.
The first is that there functionally no difference in removing Greased Lightning and actually giving the job decent recovery. Upkeep was already brainless thanks to the formshift change in 5.05 (further improved in 5.3). That on its own already killed the biggest way that GL required you to play since you no longer had to aggressively chase the boss to keep it up, and it was also a grim necessity because the upkeep tools had wouldn't have been capable of dealing with how they often design untargetable phases in fights these days (or really for most of Stormblood either). The 5.4 changes didn't change how Monk played from moment to moment at all, it just removed a bunch of points of annoyance that would have just as much been fixed if they'd given us a 30 second Greased Lightning recovery button like Enochian or BotD has.
The second reason I'd say it's a good start is that I basically didn't trust the devs to develop Greased Lightning anymore. They have repeatedly proven themselves incapable of doing it properly and repeatedly made the same mistakes. This game has had three expansions and half of the skills we have received have either been designed for edgecases that rarely come up, have been GL upkeep skills that were guaranteed to fail at their job, or have missed obvious developments on core concepts like changing Tornado Kick into a cooldown we'd earn for properly upkeeping GL for X amount of time (something I have advocated for since the beginning of Stormblood). Watching the developers fail repeatedly to expand on these core concepts has left me jaded. I've said it before and I'll say it again: Any potential that jobs have in their mechanics is meaningless if it isn't manifested, and Monk is the story of there being a ton of potential of which none is manifested. I would have loved to see them actually make something good of Greased Lightning, but at least by it not existing they can't create a bunch of worthless skills for the fourth expansion in a row. This is also the reason I want the fist stances to die, there's plenty that could be done with them, but I don't trust them to not remake Tackle Mastery for the third consecutive expansion.
The third is that calling it "a good start" doesn't actually mean that 5.4 is good. I'd almost say it's a really patronizing way of saying "For something you called a rework this is pretty awful actually". I can at least see how this will force job development to focus on different concepts or new concepts in the future and prevent the devs from falling into the same pitfalls they have repeatedly fallen into for the last three expansions. I'd also say the job also can't stay like this because as it is, because playing the job right now is miserable. The burst phase feels terrible. Chakra feels terrible. Chakra is under developed. New Riddle of Earth feels terrible. Six sided Star is lack luster as a capstone and should be at like level 40. The jobs movement kit is easily the worst of the Melee. The fist stances are still terrible and shouldn't exist. Just about every action the job has lacks impact. If Monk stays the same in 6.0 and there aren't more major changes then the devs are going to continue getting essays from me about how awful this job is for a fourth expansion in a row and the essay I already have about why the Monk playerbase doesn't trust them will get a new paragraph or two.
As for Anatman refreshing Twin Snakes being insultingly bad, yeah it is. However the skill was conceptually terrible from the get go and it's been insultingly bad this entire expansion. In the context of it being something the devs had to throw together to placate a furious Monk playerbase at the end of an expansion after screwing up catastrophically for the third expansion in a row while they save any new skill ideas for releasing in the next one for PR purposes? It's about what you can expect.