From a reader's comment to the original article:

"I am a native of Sanderson, and resided there when SP (now UP) re-located its terminal from Sanderson. Because an unincorporated town of 900 had little chance to raise the money required to undertake a restoration project of this magnitude, several in the community, including Tex Toler, Hazel Gully, then County Judge Dudley Harrison, and I began to look for outside money. We applied for, and against all odds received, a $500,000 Texas Department of Transportation (TEA-21) grant, which would have required about a $70,000 contribution from Terrell County. I wrote the grant at no charge to the County. All was going perfectly until Judge Harrison was defeated by Leo C. Smith, Jr., who, driven by his destructive nature and ally Lloyd Goldwire, caused the grant to be refused. Kenn Norris was initially supportive, but caved to pressure from Judge Smith and opted too to refuse the grant.

That was the only chance for the depot to be saved; it is too enormous a project for any local organization or for Terrell County to attempt. So, the "end of the line" for this structure, the last remaining of it kind, was reached in 2003, and can be attributed solely to two enemies of historic preservation - Leo C. Smith, Jr. (now a Bangs, Texas city employee), and Lloyd M. Goldwire, whereabouts now unknown."

In a word: Local politics and certain people in the county killed it.