Warning: long writeup
This isn’t a PvP game where fragmentation hurts matchmaking. It matters over there if you need to wait 2 minutes instead of 20 seconds to find an opponent. PvE endurance/speed runs are asynchronous and self-matched by chosen modifiers. A title like “Arena 1000 Solo Masochist HC” inherently carries more weight than “Arena 1000 SC” or “Arena 1000 SC Easy Mode”. Hades has a speedrunning community that checks a pool of 15 endgame difficulty modifiers with up to 4 ranks (heat). Most go high heat but not necessarily max (32) to avoid mods that brick their builds. Some play “fresh file” (SSF, literally fresh install) before heat is even unlocked.
Halo is even more “fragmented”; there’s Halo 5 on console, Halo 3 diehards, Halo 2 Remastered fans, legacy CE players in original graphics, Halo 4/Reach players, Forge custom map players, campaign players, even Firefight endurance runners. Difficulty comes in both traditional modifiers and “skulls” (e.g. Catch On - AI enemies spam grenades). Some people take this all the way with LASO (Legendary All Skulls On); that doesn’t make it the “authoritative” version of the game. Far fewer people would play if that was the case.
So I agree that optional modifiers could add value, just not “prepackaged” or “curated” difficulties. Solo, Hardcore, and Masochist are modifiers, not fully-fledged independent game modes with different content. They change one thing at a time and assume nothing else about how you’d like to play. For example, you can experience Masochist without losing all your items in HC, or go HC without Masochist. Some people will say “but you can’t please everyone”. This is often understood as meaning that you shouldn’t even try; just “pick a lane” - my lane. That is where the forums usually blow up. Even concessions like “optional” and “Hard mode” don’t necessarily get through.
Practically speaking, there’s no stopping people from modding an offline client. There’s no stopping “casuals” from purchasing LE for $35. Those ships have sailed. The real choice is how EHG approaches actual player behavior. They could add an official “Mod” folder or even something like SC2’s map editor or Halo’s Forge. They could neglect offline/customs and enforce a “core” online experience like PoE or League of Legends. The latter is a consolidation strategy for a “winning formula” that’s been mainstream for years. This is the idea behind Riot Games saying they wanted to make League last generations, behind real-life sports, behind those mediocre movie franchise reboots.
LE is nowhere near finished, never mind “winning formula”. Many people play it precisely because it does away with the most unpopular “features” in PoE (flask spam, splinters, doors, gamble crafting, sockets/links, trade balanced loot). It also does things that “go backwards” from that perspective (separate atlas per character, “chase” uniques, gambling, vaal bricks, mana regen). OP and others are suggesting that it doesn’t have to be a binary fork between “full casual” and “Balance Manifesto”. I would even say that both sides are not equal. A game with more of PoE’s “sticks” and fewer “carrots” can’t compete on the same axis. It needs more of the fresh ideas, and they’re harder to find when everyone plays the same way.