The failure of this game, IMO, is a combination of two things. 1. The dev team, or whoever was directing them, spent years mired in balancing and adjustment instead of cranking out new content, whether that be new ships, modules, maps, or modes. The root cause of this I will always maintain to be Progression 2.0, which needlessly introduced five tiers that required balancing in their own level as well as against other tiers. 2. Dreadnought never really gained a deeply entrenched following of dedicated players. There were are still a good number, but not nearly enough to sustain the game. I believe this is because while it is easy to get into Dreadnought, you hit a brick wall at T4. The costs associated with researching and acquiring ships and modules is on a scale that should be associated with a mature, fleshed-out game with an established playerbase. As it stands, there aren't many players with a fully equipped T4 let alone T5 and there never will be so long as the costs are prohibitively has so as to make players lose interest before they become invested.
Sometime I'll make a more detailed post on my thoughts, but the crux of the matter is that Dreadnought spent far too much time worrying about getting monetization and rewards just right and not enough time developing the game.