Honest question, why is it cool that they're re-writing?

To me this signals that the company has stagnated, or has grown beyond technology; it's an engineering team with no new ideas, no innovation, that's desperately trying to remain relevant in a company that is becoming less and less about the technology.

That's just my experience, but think about it. If a company has other revenue streams they can capture using new tech, how could they justify a rewrite vs. developing that new tech?