Again, that's just how software goes. I'm sure anyone who has released software could give you a laundry list of things he would have liked to have done, but didn't have time. Should they slide the release a year or two so they have time to feel better about how well it's optimized for speed? Generally, no.

At any rate, unless the software has been around for many decades and the best minds in computer science have failed to improve upon it, you can generally feel confident that there are tons of things you can still optimize.