Decreasing production in response to decreased demand is a fairly typical business practice, it's just good operations. Likewise, most organizations are going to decline to make major investments on new operational capacity during a down economy (there is a school of thought that says that's the exact right thing to do, taking advantage of lower costs during a recession and preparing yourself for the upshot out of recession but we'll leave that argument for another time). This is not collusion it's intelligent business operations. I know that we as consumers would like all businesses to spew out as much product as they can at the lowest price possible and margins be damned but that simply isn't realistic to always expect in all circumstances. It's a luxury that the tech consumers have largely enjoyed but that doesn't mean that it has to be that way.
Now, if all the makers of SSDs established an agreement between themselves that they would constrain production to a certain level (and I'm not saying this isn't happening) then it's collusion. There's a decent chance it's happening here, just don't automatically equate a business trying to maintain a decent margin on a product to unfair business tactics.