Did you know that in the Census, they don't actually count and quiz everybody? They get a certain sampling of people in an area and go from that. So the figures collected are not exact, never will be, but will be average for a given area. Why is this relevant to coolers you might wonder...
If you test something, or more appropriately, collect data, you don't have to mimic the exact conditions. You can collect data in known conditions and extrapolate from that how it will perform when you change variables. If you compare 2 coolers side by side @ 60 degrees, and one holds ice longer, it is extremely probable that that result will be the same @ 90 degrees, but neither cooler will hold ice as long. The better cooler @ 60 is the better cooler @ 90 as well.
Since the average Joe doesn't have a laboratory where he can maintain a 90-100 degree environment with bright sun beams shining down and a lid opener every hour, something more simple, and that can be done immediately, will give information useful to decision making, but won't be exact. However, since we have limited options and are not designing the coolers ourselves, we just want to know one thing, which cooler holds ice longer.
By your logic, you won't be able to know the results of the testing until after the season is in full swing. So if you want to buy a cooler for 2016, well you got to sit on your thumbs until summer is over, (longer since this is RTIC we are talking about) and hope someone else risks their cash to do a review for you. Maybe you can have you a cooler for 2017 at this rate. But, if you watch a test done now, you might be able to make a decision in time to buy a cooler for this summer, knowing that in about any condition, cooler A will hold ice better than cooler B.