Culture.
First, as with all companies the culture is dictated by the group you work with and the leadership guiding it. The production IT organization was always broken and never got the leadership and support it needed to grow into a first class organization like most other departments.
Second, Zillow's focus on belonging as an employee has jumped the shark, if you want to work at a company that is trying to be a full-time support group and seemingly has an HR org second in size to sales, then this wouldn't be a "con" for you.