Didn't you just release 5.5? It seems clear to me that you are unable to admit having made any mistakes. I am unsure about what you spent the bulk of your time working on in the release of 5.5, but, obviously, it wasn't on the interface, which you insist on calling a feature. You say if you could put an up-to-date-interface on the product retroactively, you would. Well, you could have done it before you released 5.5, but you DIDN'T. Unfortunately, you are simply unable to say that. It's was out of your control.

Take responsibility! I not asking you to asking you to focus on the past nor on the future, but to take take responsibility for your product RIGHT NOW, much like you are willing to take the money you charge for it. Can't you do that? Can't you say, we recognize the interface is sub-standard, and we will focus, right now, on fixing it? Wouldn't that be better than saying, as before, ...it was out of our contol...we just bought the product {before we sold it to you}...we can't be wrong...wait for the future? Why won't you commit your resources to focusing on this NOW? Don't your customers deserve that?