I think unfair is OK on its own to describe a green like 18 at Olympic when its cut too low. I'm just not a huge fan of the "tough but fair" moniker. Its absolutely meaningless...so much so I got a crisp $100 bill sitting here for anyone who can succinctly define it.
I don't think it's particularly difficult to define. I think most people have a "sense" of what it means, too.
Tough but fair is two things: tough and fair. Tough we can agree on, right? So the real question is defining "fair"?
To that, there are two possible definitions. One is that everyone plays the same holes under the same conditions, or as close to it as possible. (The weather at some tournaments, particularly the British Open, can sometimes be "unfair" if you're on the wrong side of the draw.) The Rules of Golf are "fair" because everyone plays under the same rules.
But the tougher definition is the semantic one, and my stab at it is something like this: the results of shots are generally rewarded or punished relative to their quality. As with the Rules of Golf, like situations are treated alike. To many this might mean reducing luck - two equally good shots don't result in one shot being four feet from the hole and another shot bouncing OB.
Note: I don't mean for this boundary or gradient between "luck" and results or whatever existing everywhere. Obviously, for example, if you have a cape hole, a ball that is 1 yard over the water on a line is a great result, perhaps, while one 1 yard short is a horrible result. Those "lines" or edges will exist everywhere - a ball a foot further up on a green at Augusta National will stay while one one foot short rolls off the front. I'm talking about play away from those "edge" cases, or minimized "edge" cases. If the majority of shots introduce these "edge" cases, the course is fluky and prone to "luck" more than skill. You won't ever eliminate luck entirely, but a "fair" design, IMO (as all of this is), reduces it to a manageable or expected level.
Need I go on? We call most of the above rub of the green and some we might just call poor design or stupid setups.
No, we don't. Not the rules officials among us, anyway. Kinda ironic you're complaining about the use of the words "tough but fair" and then take this misstep.