Change orange legendaries

[Forward]

Is that bad thing?

Are you joking?

Half of the game's progression In items is currently not relevant. 

Why buy [most] of the Green items when a lot of Light Blue are so cheap
Why buy [a lot] of the Dark Blue items when some Orange Legendaries are so cheap
Why buy [some] of the Orange Legendaries when a few Red Legendaries are so cheap

Half of the game's models are not being used/wanted.

It happens in all games. And in many games not-highend items worth nothing, so NI economy is great in this regard, thanks to upgrades gold/mats sink. As being said in another thread, many NI features are not working like was planned initially, like crafting, house system or 16 hero classes. The game also doesn't need so many items apparently, like your Kriegsmesser example. But it's a mod, not AAA game, so you might expect some flaws. If NI2 will happen I'm sure developers will learn from NI1 mistakes. Some of problems of 2020 were impossible to predict in 2013, but orange legendaries problem is less important amongst them.