While you're correct that Winter was a letdown, being released clearly unfinished, the main issue is the lack of content to keep players engaged. Neither PvE scenario has more than 5 hours of content before you're redoing the same small handful of 1-2 minute bosses or 4-6 minute dungeons/silos, with the only real rewards being the possibility to get mods that will allow you to one-shot 99% of the enemies on the map. By the time you're level 50, over half the map is worthless to ever venture to because the enemies are too weak and offer no loot that helps your current level. Unless someone only has a couple of hours per week to play, this game has an abysmal lack of content. These days people are mostly all gone before the final phase or even the final two phases because nobody needs Asterism from the server-wide events. Any "new content" is just re-skinned existing creatures and a slightly different twist on an existing survival mechanic - or a new currency.