Never underestimate the power of internal company politics? Jokes aside, I do agree with you
My only guess is sunk cost fallacy sprinkled with some corporate hubris.
Unfortunately the sunk cost fallacy is often rational when you consider reputational consequences of the individuals making decisions within the company.
It's pretty easy to spin an easily reversible decision as "complicated" and "a bit messy", but you'd get fired for taking a risk and wasting years.