When a tour gets cancelled you take work away from the drivers, sound engineers, stage crew, caterers, security, lighting engineers, merch staff and many, many more. They're not salaried, they're paid hourly.

Macklemore was never gonna get to play, either he was dropped or the remaining US tour dates would be cancelled. This does the least damage to all the other people.

What Sheeran should, but didn't, do is vocally support Macklemore. That's what he's done wrong here, in my opinion.