Recently it was mentioned DE is trying to limit the FOMO (Fear Of Missing Out)... however nightwave fundamentally is an engine designed to play on FOMO. It uses rewards that are timed exclusives to draw players back to do a repetitive task that they may very much be getting tired of. At the core of the problem of nightwave I think is that it is time limited, and exclusive.
From a developer and investor perspective this looks fantastic because playtime numbers skyrocket, however many of these (in some cases all of these) hours are spent doing annoying, slow, repetitive, and sometimes tasks that are down right against what a player should be doing for their account progression. (3 forma for a player who has forma'd everything, gilding weapons when they have mastered them all already are some examples of how this wastes a players time and resources for a minimal reward)
From a new player perspective (followed two newer to the game friends around) they never got past seventy percent of the nightwave due to their day jobs, much less finish it, and it drastically slowed their progression down and all of the friends they were playing with no longer wanted to play with them because they were too busy trying to complete nightwave, rather than get through farming or story like the new players were focused on. This effectively alienated the newer players in my friend circles. These new players didnt care for the nightwave much, and were slightly bummed out at missing the rewards, but that was fine, to both of them.
From an end game players perspective, this is a horrific system. Nightwave gives the one thing an end game player cares for: cosmetics. This on its own would normally be fantastic, however when combined with being time limited, and forcing a player to do tasks that they have done potentially hundreds or thousands of times before just by playing the game, does burn them out. EVERY END GAME PLAYER I KNOW AND SPOKE TO HATE THE NIGHTWAVE because it forces boring and repetitive tasks onto the player that is the most likely to get burned out from the game and want to take a break, only to punish the player that takes a break to come back to enjoy the game later by not allowing them to have the one thing left for them to do in the game - get more cosmetics and customize their account.
As a note from the end game guys I have been talking to, three of them are world of warcraft veterans that have been playing since release and only quit three years ago, and currently play path of exile, every season. It is my belief that if after about four months of something players like that are commonly tossing around phrases like '$%@# nightwave' 'nightwave sucks' 'I dont want to play warframe' ' and 'nightwave is &%#$', wanting a revertion to the old system, you have failed to truely do what you set out to do. You have increased playtime, however it is time a player is misserable. The goal is to make a system to make players want to play. these words are important. Want to play. Currently the system makes players do what they feel they must do or miss out on the one thing in the game they have left to do (cosmetics).
Now for the difficult part, trying to offer feedback as to how to fix the issue. Currently the issue I see overall is its burning out players faster than ever before, while not allowing them time to come back to the game later when refreshed because of the fear of missing out. The only way I know of to make this system not burn people out is to remove the exclusive items, or remove the time limitations. Burnout occurs when a player is pushed to do things they dont want to do, or to do them faster than they want. For this the only solution I see is to make the rewards you can aquire from nightwave more desired, possibly add repetetive farms a player may be optionally interested in like nightwave credit reward purchases like boosters, kuva, or raw resources. including all resources that are new will also allow a player to farm in an alternitive way to enable them to prevent their own burnout. this must be balanced for time spent farming either way to make it roughly equivilent, and just allow what is preffered. provide the player options. cosmetics in the nightwave are not out of the question, but should make returns for players who need a break. perhaps added as a tactical alert once annualy to get what you missed that is not otherwise farmable, or to have exclusive to nightwave items always in the credits section at a high price, but not too high that it is not feasable to catch up after taking a break.
Fixing this system is really quite a challenge, as it is a system other developers use specifically to boost numbers and play on peoples fear of missing out on their favourite game. For the reasons above, I have personally decided to quit warframe as I am an all or nothing kind of guy that values his time. If this all gets fixed I would love to get back into the game, however at the current state, even with the latest teasers for railjack and new war etc at tennocon, I just dont see myself making it there before I burn myself out completely and never want to touch warframe again, all the while hating the nightwave. The whole thing has drained me of my desire to play even other games, and I find myself rathing to go for a walk than to sit and play a game because I know at a certain point i will go do daily login, etc etc, and be shown the nightwave i would be missing out on. Please, fix nightwave so it lets people come back in a few months and catch up.