Yes its [DE]'s Job, well... their design teams.
Warframe is a action based third person shooter with a focus on gear progression and challenge/difficulty is what drives the player to obtain better gear. Without challenge/difficulty there's no reason to play the game. Obviously the progression cannot be endless but there should be content that should be impossible to trivialise and will always pose threat to the player to give them a reason to try get stronger.
For those who are playing what's your end goal when playing the game (I'm genuinely curious )? - If its 'Fashion' then you don't really have to play the game 90%(My rough estimate) of the fashion is acquired via 'Credit Card Poweeeer!'. The others are supposedly acquired through some kind of achievement and is meant as a form of badge of honour(virtual street cred?) but if they were easy to obtain its worth is reduced(which many of them are). - If you're playing for story you have my condolences. Story content is slowly drip fed to us and lacks and lacks any kind of real flow resulting in a messily told story. Sure the universe is interesting but there's far more games with a more interesting story and better flow which doesn't keep us waiting a year plus for a 1 Hour story quest - If you like the content being easy then why not keep playing on Earth? I mean seriously if you don't want a challenge you have no reason to try becoming strong enough to venture to other systems. If you believe this is unreasonable I see it being equal to asking a player to gimp themselves to feel challenged in Warframe (I'm sorry if that came off as rude).
Balance in the game is all over the place and the [DE] team is too spread thin to truly address this issue a single Warframe shouldn't be able to complete a mission while the player is AFK, this doesn't make for interesting gameplay and neither should a single player take control of a entire mission in Co-op leaving the other 3 with nothing to do.