Which is dead wrong, because not only is there no usable definition of "improve itself", but there isn't even any understanding of the kinds of skills required to create a usable definition.
It's the difference between a computer that is taught how to compose okay-ish music, and a computer that learns spontaneously how to compose really really great music and do all of the social, cultural, and financial things required to create a career for itself as a notable composer and then does something entirely new and surprising given that starting point.
They're completely different problem classes, operating on completely different levels of sophistication and insight.
A lot of "real" AI problems are cultural, social, psychological, and semantic, and are going to need entirely new forms of meta-computation.
You're not going to get there with any current form of ML, no matter how fast it runs, because no current form of ML can represent the problems that need to be solved to operate in those domains - never mind spontaneously generate effective solutions for those problems.