You shouldn't have to use engineers to play ED but hey ho, FD forced thought this dlc was a great idea make ED more 'meaningful'.
You don't have to use them. Point in case: whenever the game gets a new ship, i first take it to a two hour tour or so to a RES. Non-engineered. Only when the ship performs well and i like the profile, it is kept and engineered. Despite intentionally taking on the hardest enemies in HazRES to really see what the ship can do, i have not yet lost any of the non-engineered new ships there. So if a mediocre pilot like me can take on elite Anacondas in non-engineered ships, it's not like engineering is absolutely required.
That being said, i also think that engineers did more bad than good for the game. Their mere presence is fine. The process of engineering is much better than it was when it was introduced. Of course people had some awesome ideas on how engineering could be even greater, but it is what it is: most of those ideas would require huge additional effort to implement. FD is better off creating new content, than reworking engineers once again there, i guess.
What i really dislike about engineer is the insane power scaling. I mean, if they'd provide like 10% or 15% more of offense and defense, they would already be awesome. A fully engineered ship would already be a real advantage in a fight. (In other games, people go for great lengths to get a 1% advantage. ) But we can have like +700% on defense. That's way out of scale.
So yes, reworking and nerfing blueprints would be perfectly fine for me. But unfortunately there's a vocal part of the community, who successfully cried away even small nerfs. An actually full scaled nerf would result in a riot. I doubt we'll ever see that happen.