I think that the crux to the above problem, that many players enjoy elements in a game that reviewers rate negatively, is to an extent a result of the review process and having to finish a game relatively quickly, thereby making games such as Mad Max inherently difficult to appreciate beyond their central gameplay mechanics or hooks. By looking at its composite parts, certain reviewers and players may not get the same fun out of Mad Max' overarching open-world setting, ambiance and free-form agency (could also just not be your thing if you like linear experiences, that's cool too).
If you critical path it, the game is not going to be fun because its story serves the gameplay. If you go completionist on it, it's going to be tedious. It's a blend of the two that can be pretty fun. As weird a comparison as it may be, if you play Animal Crossing solely by earning money, paying off the debt and collecting furniture, you will encounter the same gameplay loops over and over, or run out of stuff to do in a day. Fishing and digging holes is not what the game is about. There is little to no skill involved and from a pure gameplay perspective not super fun. Most people understand this and approach this series from a different standpoint. Instead, the optimal way to play Animal Crossing is focusing on the things you enjoy doing, look around town at what's new and chat a bit, dig up some fossils, etc. and call it a day. Rather than the game explicitly setting goals for you (apart from the loan), you set your own and dictate the pace at which you approach the things the game has to offer.
It's similar in Mad Max in the respect that the world is quite large and the things you can do are manifold, but if you start doing one after the other it becomes a repetitive timesink. Unlike reviewers, regular players don't need to think about a deadline to finish this game by and have the luxury to try a bit of this and a bit of that. Rather than writing down 'well the combat's not as good as in this other game that's similar' and thinking of it in a more rigid, checkboxy kind of way, I think that most players (as in not reviewers) are not compelled to qualitatively assess each element of a game and just take it as they go. It's why dumb action movies are fun if you don't get hung up on logic and shitty dialogue or whatever.
Mad Max is also not about filling in markers on a huge map like Jim talks about. That is missing the point of these kind of games. You're not obliged in any way to all of these things unless you set that arbitrary goal for yourself. When you want to have fun, you ask yourself the question of what you can do to enjoy yourself, not how fun doing X is for Y amount of hours (unless you're a machine). So, what it comes down to I think is that Mad Max is better than the sum of its parts, which individually I think everyone has agreed are nothing new, but if you've been cultivated to think about games in that way or approach it from a similarly restrictive pattern of thinking, it's unlikely you'll enjoy it. Another factor of some importantance is the fatigue reviewers get of having to play games that have very similar loops between one another. Many people won't have played Shadow of Mordor, Assassin's Creed Unity, Arkham Knight and all those within the last 12 months. If you don't and you don't feel obliged to make every purchase a highly critical value-based judgement, you're not gonna feel like you should have bought this or that game instead because some individual elements (that aren't actually directly transferable because context matters) are better, or whatever.
In short, the way you approach a game matters. Don't do shit you feel gets repetitive, because there's other less shitty stuff to do. Be creative, go sightseeing or something. Ultimately it's not reviewers who decide if a game is good or bad, but you so who cares anyway (but because so many people only let reviews dictate what they do and don't like, mediocre reviews will hurt sales, yes).
That Codemasters game, Fuel is another example of the above. Arguably not a great game, but you'll find a lot of people who enjoyed the hell out of driving around the barren open world just looking at stuff, or finding a group of likeminded people and take an online road trip together from one corner of the map to the other.