I agree with most of your balance points, in particular the engineering vs. vanilla skew, and I am possibly the most vocal defender of mining's profit on various elite related subreddits. I have also posted there a lot research on the new mechanic that was very popular (will provide links if requested if you won't take at face value).
But I also enjoy pew pew pew and your painting the whole aspect of the game with one big brush is very inaccurate to many of us who have no interest in seal clubbing. I hate the engineering requirements myself. I think blaming some truly poor design decisions on FDev's part on us "pew pew crybullies" is inaccurate.
Also, at least on PS4, it's virtually impossible to find miners to gank. I know, not because I gank them, but actually try to find them to pirate "by the rules" (e.g. use comms, not a murder build, don't open fire until reason to, etc). It's way way way way harder than mining which I've also done a lot of, possibly more of. When I've interdicted at CGs or eravate, usually these result in friend requests.
I've found a few miners, but always only with limpets. And now that there are 39 stations to sell at, I can no longer find any at all. I know PC is different, but are there really that many gankers 180 ly out from Shinrarta where some of the sell stations are, even on PC? (I realize I could be wrong here, having not played on PC)
For the record it's completely viable to mine in open with engineering. I can provide combat capable builds on request that I have actually used to make hundreds of millions. By combat capable I mean, can kill a poor to medium skilled gank, have a decent row with a decent ganker, and flee from any except for a *very* good wing. Obviously for the non flee options, there's a big time investment. Learning to flee takes a few hours max to someone already well versed in other aspects of the game (enough to mine successfully).

Sorry mate, I didn't mean to strike a nerve!
I'm not claiming 'pirates' or guys interested in PvP are
all seal clubbers. What I am saying is that for three years the overwhelming majority of the development effort in Elite seemed to be directed towards aspects of the game based around combat. Funnily enough, most of the 'improvements' seemed to mirror lobbying on the boards and forums about what combat players seemed most interested in. Crafting and then engineers seemed to be skewed towards combat applications, nerfs and buffs to ships were in areas that directly affected combat performance, new content like surface installations came with armed targets to shoot at... there's a whole lot more but I don't want to re-open old wounds. Just go back a few dozen pages on the main board, you'll soon see what I'm talking about.
From time to time profitable opportunities came up. Things like smuggling and passenger missions got nerfed into oblivion after months of loud complaints from people crying about not being paid to use all the new upgrades to their kit. They got the lion's share of development effort, they wanted 'gold rushes' to go along with them and mounted weeks long temper tantrums when other (lesser?) styles of play got rewarded. Ironic, really, as the goldrushes were usually a pretty transparent attempt to hide the complete lack of content in those 'lesser' modes.
Looked at another way- the gap between non combat builds and min/max warships has been getting larger with every patch. The guys flying ships that are useless at everything bar destroying other ships are extremely vocal- check out who's starting all the 'miles wide, inch deep' threads. Mostly they were the same guys throwing teddy out of their pram because newbs were (allegedly) coming by credits way too easily, or people were 'getting away' with using what they considered unsuitable builds in player groups or solo. Vitriol directed at the mythical 'unshielded trader' apparently undermining unspecified factions was liberally splashed around this forum and others.
Again, I'm not going to go too far down that road, there was a lot of bad feeling on both sides. But Frontier have spent three years increasing the options and amplifying the differences between non-combat and combat orientated ships. It's very hard (for me) not to feel that 'pew pew' has gotten far too much attention from the company and I can't help but notice that many of the new ideas seem to have been mooted on here a few months before they appeared in game.
Personally, I got really bored of calls to nerf everything a long way back. I'm pretty sure the next patch will kill the void opal goldrush, but even if it doesn't, miners making fortunes doesn't bother me in the slightest. I'm very suspicious of those who do complain, though. What's their objection? If it's jealousy, an irrational anger at someone being rewarded for doing something that doesn't involve blowing up kiddie on spaceships, then I'm calling them out for what they are!

Meanwhile, I'm really happy with the latest season, or whatever it is we're calling this year just gone. It's had a ton of really cool stuff and miners have finally gotten a wee bit of love. I'm all for that, even if it has taken four years to land. Better late than never...