There's also the fact that new players just can't afford anything. Prices are high from the gold buying days, and new players coming in have no means of making gold unless they get lucky on drops, which means that most don't have the means of paying high prices for anything.Most items in general aren't selling very well because of how dead the game is.The main reason i could think of why they remove giving matts after "boom" is because of the "seal shop"This is exactly the reason why we are no longer getting materials back after booming. With all the handouts this game is already giving out, its already killing the market as it is. OJ's are literally next to impossible to sell or you have to sell em dirt cheap. The only thing worth any sort of value now is dyes and mysterious shards and even those are having a tough time selling.
this are just my opinion
1. To encourage other players to keep doing raids.
2. Over supply of rare matts on mp. if players keeps getting their rare matts after item destruction
3. Rare matts value will go dert cheap. actually its very cheap right now it will go much less of a value if we still keep getting our matts back.
4. since all matts are cheap its not really a big issue if we dont get our matts back.