I get that it's a prioritization issue. I've worked at places where legacy software had poor security practices and it's often a judgment call as to the risk of just letting it be vs. taking the time to rewrite whatever insecure portion remained. Often the decision is to leave it when it's a one-off project that will be shut down within a month, there is a limited attack surface involved, and the data being stored insecurely is very low value. On the other hand, security issues affecting the very core of a website (the login system that 100% of a company's revenue depends on) should get addressed as soon as the vulnerability is discovered. Additionally, they state that a server was compromised... it's not clear whether this was a SQL injection exploit that happened to display the users table remotely with no privilege escalation, or whether the server was compromised via a poorly chosen SSH password or similar and they may be dealing with a situation where rogue code is still living on one or more servers.