IRR is so trivial to manipulate - it'd be wonderful if more investors began demanding actual metrics on capital performance. If you're parking cash with an investment firm you want to know about how much of a return you can expect when it is withdrawn, and while history is a guide and not a guarantee, there are much better ways to inform that expected return than IRR. "My million got a return of 2% during a year when your reported IRR was 10% - where's the other 8%!" is a common cry from those who haven't just rolled over their investment, unaware of how little it has functionally appreciated.