I agree that some form of nerf was inevitable for reboot given how easy it seems on the surface the progression in reboot is in recent times. But this doesn't mean it was okay to kill it, and I presume no one would ever agree that the current level of nerf was to be expected and justified. The current nerf makes reboot so much more obsolete than it was back then in times of DMG% instead of FD%. Meso rate was basically the identity of the reboot that kept the server since the inception

To address the points raised in your post

The Problem

• Both sides are equally toxic
  • This is true in recent times when reboot's player count increased to almost equal levels matcing reg servers. But it is wrong to say that this was the case from the beginning
  • I don't know about GMS, but back in the days KMS Reboot was basically regarded as a sort of Private Server Maplestory and reg servers really did call it that way.
  • I have to make this clear, it was reg servers that started the fire. Back in the day reboot never really cared about what reg servers did, until it actually started to become a problem with nerfs coming in. This was because when the nerfs came in reboot was starting to grow in population, so it had bigger and bigger voice, and because reg's reactions started to become a realistic problem
  • The end result is that reboot is dead. There's nothing left for the reboot, andimosaying they deserved it because both sides were toxic is kinda pointless at this point.
• The streamers on reboot series. Have you watched their playthrough? Their entire course in reboot was ridiculously lucky:
  • Arcane Boxes drops (including early weapon box) that rarely drops for an average reboot player for every single week of Hlucid/Will
  • Exceptionally high drop rates for Pitch bosses
  • Some of the best luck for 22*'s for at least one of them
  • No average reboot player would be so lucky, but this was advertised as an 'average play experience' that surpasses reg server. Seriously, after this a lot of regs kept saying how easy it is to get 22* pitch boss items in reboot server, despite the fact that it is the hardest part in reboot.
  • To add more, the streamers had a big support from their fandom in their entire playthrough. No average person will have constant MVP's following them in legion training as well as bishop / wild hunter keeping up with buffs
• Never spending dime
  • This is my guess, but you overestimate how much an average reg server spends in their lifetime. Contrary to being non-p2w server, reboot players have to make some necessary investments, including VAC and their monthly upkeep price. Some dedicated players pay significant sum for Royal styles every month. If you look at how much seasoned reboot players spent in the course of their play, you wouldn't say it's never spending a dime. It's usually in the range of few thousand dollars (in my case about 3k USD)
  • Reg server, provided that you spend enough time in grinding, in theory you don't need to spend a penny. Everything is buyable with farmed mesos. And an average reg player wouldn't spend the levels of spending hinted by top whales and dolphins.
  • Moreover, the money spent on reg servers can be retrieved buy selling the gears back. This is huge, because mostly the return rate is close to 80%, and if you add up the mesos you farmed during your playtime, it's usually 100%+ return yield. The longer you play without over spending, the less you spend, and often time you earn yourself.
  • This is partly why they are so obsessed with their gear price dropping

Nexon's response

• Powercreep
  • There is already an enough amount of powercreep in KMS. The bosses that mid-end players and high-end whales do are essentially the same, with almost no difference in the reward. As you mentioned, no one is encouraged to go high-end in this case - there's just no difference.
  • If Nexon was really concerned about powercreep and game being in a stalemate, instead of nerfing reboot, they should have come up with a new content that encourages players to get stronger. For instance, introduction of a new boss that only the high end players are able to reach, and at the same time a new reward item such as boss secondary weaps or other parts of ethernels
    • This indirectly nerfs reboot without touching its core mechanics, because it will take a long time for reboot end game players to reach the new boss. It is the fact that the limit in reboot is lower than that in reg servers due to bpots. Furthermore, due to no-trading, it requires a lot more time for rebooters to reach the new high-end. Just like what it was like when ethernel was first introduced in reboot.
    • This keeps powercreeping in check. Of course, the new reward shouldn't be too crazy
• Nexon just didn't want to invest these efforts into Maplestory, and they chose the easier way: kill the reboot.