Usually 2 is allowed for same rate but I imagine if it’s “business” hotel that targets a single business traveler, then perhaps that’s their policy. In any case, it should have (and I assume it was) made clear at the time of booking.
Discussion
Yes, at least it’s clear so I asked before booking.
Well, assuming there is bigger cost for having 2 rather than 1, the fact that the price is standardized to always allow 2 in some places mean necessarily that people that go alone are basically paying for the price of 2.
Can’t imagine why it would cost that much more for 2. Unless breakfast is included but otherwise should be covered with any standard markup. Hotels get bulk deals on the rest of their stuff.