I think the issue is that business surplus concentrates power to a greater degree than consumer surplus. Concentrated power, be it a business, a government, etc

I think the issue is that business surplus concentrates power to a greater degree than consumer surplus. Concentrated power, be it a business, a government, etc is typically bad because it can be used to distort the market in its favor (i.e. corruption). So it makes sense to me why even folks who favor efficient markets don't want to shrink consumer surplus, at least not faster than business surplus. In the case of a single restaurant like here, I don't see a huge issue though.