Hm... I wonder what armor and hull is made of... Ah yes, metals... Now, how do I get those metals? I wonder... Maybe mining... dunno...
Hmmm...I wonder what almost every piece of equipment on every ship contains....ah yes. Metals.
Nice try, but your comeback wasn't nearly as clever as you think. Selene is not unique for wanting metals to make stuff so this isn't a sick burn. My point is that engineers require specific gameplay that is sometimes completely unrelated to the rewards they unlock. If a dedicated miner sees Selene and goes "ooh, she wants me to mine! Cool! I wonder what she'll give me? Better mining lasers? A new kind of refinery? ANYTHING TO DO WITH MINING?"
Nope. Just reinforcements. The non-miners probably hate having to mine to get them and the miners probably don't care about them much. That's terrible in my book.
Contrast that with, say, Felicity, who wants you to get some exploration rank and provide a meta alloy, both of which require a little searching around and more than a few jumps. What's her specialty? Frame Shift Drives. You know, something that directly affects your ability to travel and explore?
Or perhaps...Tod McQuinn. What does he want you to do? Go get some bounties and bring him some as proof. What's his forte? GUNS. Multicannons and rail guns above all. You know...stuff that's good for bounty hunting.
I could go down the grid, but the point is that some engineers have a clear connection between gameplay and reward. Some engineers have none at all--like Marco, for example. What does he want? A rep grind and cargo that can only be gained from odd mission rewards. What does he have? Powerplants and distributors--BOTH of which offer lesser grades than you're likely to have from other engineers--and NOTHING ELSE. He's worthless. There's no need to even pin a blueprint from him unless you REALLY want some very specific stuff from other engineers AND are willing to settle for G4 or G3 stuff. (a lot of us probably aren't.)
But if you want those G5 thrusters from Palin (and you do because they're worth it) then guess what?
You're damn sure forced to deal with Marco first. THAT is forced gameplay and it is an abomination.