Well, I'm certainly not saying that WDT is, or is not, going anywhere - time will show that. But I think the current CEO agreed with you when he arrived (or so it seemed to me), which is why he changed the company to be totally customer-focused and is now going for profit based on being a good company to deal with on all fronts.
The electricity cost of running endless store freezers is hardly chickenfeed, which is WDT's first selling point. Now add in a strong customer support team, price competitiveness, and now extras like remote monitoring and promotion beacons. I'm guessing that smartphone in-store promotions are a big thing for the future, just as I'm guessing that THL's togo app is going to draw in a lot of revenue too. But nobody knows that and only time will tell.
But as to what WDT offers that is special? I would have said it was the total customer focus which has become their hallmark (to judge by the company reports). People love dealing with companies that are genuinely on their side. My view anyway. I never claim to be right.