Agree that the random element introduced with engineers is ridiculous... but to me, more egregiously, is how it completely unbalanced pvp with no hope of it being "re-balanced" (some may argue it wasn't balanced previous to engineers!). Simply put, engineers was a "content addition" done with little consideration for game balance but as a benefit to the devs, would cost very little (development wise) to do. There's very little actual content to it at all, and engineering boils down to long range fetch quests with crummy rng as the reward.
The thing about Engineers...first off, they are misnamed. They should have been called Tinkers.
Second, I don't think FDev ever intended, or even envisioned them being used in a min/max capacity. They were intended to be something that added a bit of variation between ships with some minor pros and cons, improvement here, draw backs there.
The biggest flaw in Engineers was how Frontier, as they are soooo prone to doing, grossly overlooked how these things work out in every other game out there that allows for a min/maxing mechanic. Add to that, Frontiers implementations often require some sort of artificial incentive to get people to use them, so they added significantly higher bonus' to entice people past the entry requirements for the higher level mods. This in turn led to grossly over powered ships, with so many different moving parts, stacking, bumping, tweaking, that finding any semblance of balance is near on impossible, not to mention the disparity it created between Engineered and non Engineered ships...and it just went on from there, creating a virtual arms race.
I am pretty much a PvE only player who's main focus is Exploration, and don't tend to be a min/maxer, and so playing the Engineers for what they are, and for what Frontier originally envisioned them to be...I actually quite enjoy them. I have myself a very nice, solid AspX with a 55ly jump range that can boost, cool running, SRV, AFMU, Shields, Mining Laser, and I only unlocked two Engineers, only have two grade 5 mods, the rest are grade 1 or 2. I had to do my poking around doing things that I never would have done otherwise, but was able to get everything I needed in more than enough time before it felt like a grind. My other ships, including a racing eagle, a viper mkIV, and a Fer-de-Lance all have minor mods that make them excel in the PvE activities that I do.