ServiceNow Staff Software Engineer interview questions

The process was straightforward: phone screen, meeting with the hiring manager, three more interviews with team members and department head involving technical and behavioral questions. However, at the end of it all, even though they said they wanted to proceed to hire me, they stated they did not (yet) have a budget/headcount available for the position and wouldn't be able to make an offer until next quarter IF they get the budget... so why were they interviewing for the position now in the first place? Frustrating to have spent all that time interviewing only to learn this AFTER the whole process.