The usual reasons: maintenance costs on the old unused gear, environmental concerns of new construction, locals who don't want it, partnering with a transmission company, partnering with a distribution company, getting the capital to pay for it all & the feasibility of financial return, among many others.
There are hundreds of potential projects like this they could invest in. It's very likely that one of those other projects is way more likely to succeed, so they pick those projects, and take this one as a writeoff. They could possibly still come back to it, but probably not.
