This is according to a post made on Reddit in which Saurik announced that one of the reasons behind the shut down was due to the fact that this was a money-losing endeavor. “The reality is that I wanted to just shut down the Cydia Store entirely before the end of the year, and was considering moving the timetable up after receiving the report (to this weekend); this service loses me money and is not something I have any passion to maintain.”
Saurik adds that shutting down the store was something that he was planning to do for a while now, but that timetable has since been moved up due to a recent discovery of a security vulnerability. He stressed that this is not a data leak, but pair it with his loss of motivation to maintain the store, it sounds like it was not worth the hassle of him trying to fix it.
Note that the Cydia repository itself won’t be going anywhere, it’s just that users will now no longer be able to make purchases from the store itself, but they’ll still be able to download previous purchases or make purchases through third-parties.