No, they are closing because the owners want to retire. My brother-in-law owns an Ace affiliated HW store in northern Idaho, and the owners talk. The Pullman owners have wanted to retire for quite some time, but have been unable to find someone to buy/takeover the store.
And for the record, Walmart is not a significant competitor to Ace. My brother-in-law's business does just fine with a Walmart in his town. The competitor to Ace was the the giant expansion of the Moscow-Pullman Building Supply that opened between the Walmart and the Ace. That used to be a relatively small hardware store next to Pufferbelly Depot. But their Moscow store was gigantic. And then they built a new place, much larger than the old. But regardless, the Ace did just fine.