Why would having those skills alter the value of recovered ships? You would be deploying your officered, pristine ships so they only value those recovered ships would offer is shifting the DP capacity towards your favour. There's not that much difference between a ship with 4 d-mods or with 2 d-mods that would turn one from not much value to insane value, especially if you will never deploy it. Even with 7 d-mods, a ship will still be about 70% of their original value, but that doesn't matter by the time you are facing these end bounties as you would never deploy them and are normally aiming to not suffer a single loss.
Why would d-mods effects reduced by 50%. Perhaps a removed skill?
In reverse order:
There is a current skill that reduces the effect of D mods by 50%. (This, combined with other skills, makes Increased Maintenance actually save you supplies if you fight once every month or so, which is a fun bit of trivia.)
Without industry skills, a recovered ship will typically have 3-5 D mods, which significantly degrades their combat power. Because officers act as a power multiplier, that degradation is similarly multiplied, and power concentration is absolutely key. Heavily D modded ships are, honestly, not very useful beyond distracting the enemy (and they suck down fuel). If I'm not playing an Industry build, I don't recover anything but the rarest, least D modded ships.
With Industry skills, a recovered ship has 0-2 D mods, all of which have their effects reduced by 50%. These ships are much, much more useful. I'm not claiming they are
as useful as a pristine ship, but they are extremely close. And several of the possible D mods become almost beneficial, because they have negligible bad effects but reduce both deploy and maintenance costs. And there is a decent chance of getting a pristine ship anyhow.
I was very surprised when I did an industry playthrough just how much better recovered ships become. But its a lot.
Even if you have industry skills, you can only deploy a certain number of ships and have a certain number of ships in your fleet. At some point, the ships you have in your fleet are just better than the ships that drop (and that happens very quickly in my experience). Once you've converged on your 'end game' fleet, you have no need of other ships. Unless you're losing a lot of ships, endgame salvaging is just not very useful because you just don't need more ships. The only ships you salvage are rare ships you don't have access to, and you intend to restore those so its definitely not profitable. In my experience, the top tier bounties require something near an 'end game' fleet to defeat them so the salvageable ships are mostly useless at that point.
Even before end game, I usually am aiming to mostly have ships that are much better than the average d-ship so d-ships very rarely represent any improvement to my fleet. The only time when I'm happy to take d-modded ships is very early on when I don't have enough ships to use all my deployment points and I need 'filler'. After that, I'm looking to replace d-ships with good ships, not add more.
The key point here is "at some point", and that the recovered ships are often pristine or near enough pristine to make only a small difference (see above reply: the recovered ships are not bad). Any time before that point, recovering a near pristine or pristine ship is worth exactly as much as it would cost to buy it, which is several times the payout of the bounty in most cases: a 200k bounty might give 1 million in recovered ships, even if I'm being picky about which D mods I accept. A multicapital bounty... gives multiple capitals at near pristine levels. There's no need to ever buy or produce ships unless you have a rare blueprint thats not showing up in bounty fleets.
After you have no need for more ships... well the game is over because you can smash any fleet into tiny little pieces with little effort. I happily admit that Industry skills don't help much at this point, but theres not much difference between being twice as powerful as the enemy and 2.5 times as powerful.
