In MOO2 you can gain tech from captured ships when you scrap them. I'm sure the devs know this as they talk about MOO2 all the time. I agree that they've probably thought of it, maybe even implemented it, but couldn't balance it.
For my part I think it would balance alright if you could decomission the ship, and then have a random chance of gaining a random tech that was involved in the construction of that ship. If the ship has a high level mass driver tech in it, and you're focused on missiles or beams, if you randomly get the MD tech as your bonus, then you get an increase in YOUR level of mass driver, not a copy of the other player's tech. So if they had a +5 MD weapon and you've only researched +1 MD weapons, you might get a +2 MD tech out of it.
But you have to scrap the ship, and that's the key part. You could take it a step further and make scrapping a ship for tech and scrapping a ship for money separate options...so you might scrap ships and not get anything out of it.