From a game point of view, it heightens the "rich get richer, and the other guys lose faster". Too much of that isn't fun.
Why? Easy... the more of their wreckage you crawl, the better your ship tech gets. For you to have a survey ship to crawl their wreckage, you either a) Own the skies, or b) are on friendly terms with them. Otherwise, they'd blow you away. What's this mean: 1) you are blowing them up already, so you don't need help getting further advanced in the game, or 2) you are just benefiting from someone's aggression. In the case of #2, you can just diplo the aliens to fight each other, and harvest all their ship techs! That might sound fun (it does to me), but it means that playing the aliens off each other just got another reward. Does it need more bonuses? Isn't being the primary trade partner of the map, and the guy who is out teching everyone else be enough of a reward for that strategy?
Having the wreckage be a "wreckage" anomoly would fine. Except for the "random ship" result. How does a destroyed scout turn into a corvette? It wouldn't. So small change to wreckage anomoly to keep it non-cheesy.
The least game balance change seems to me to be extra BCs. After that choice is the small, random tech bonus. But a small tech bonus would be worthless past the early stage of the game. What's 5 or 10 RP when you are making 100 a turn? If techs were randomly determined, then I'd suggest searching wreckage could "open up" one of the techs found on the ship that you don't already have (but low probability, so you'd need to search many such wreckages before you'd get it, on average). But techs aren't. So what's left? EQ for your survey ship so that, by the end of game, it has Missiles +100, Hull +350 and PD +85, and can beat up your opponent's best battle stack by itself?