The point is that when you take a series of measurements, then aggregate them into a score with arbitrarily chosen weightings that aren't universally applicable, the scores are useless.
Just doesn't follow. The score does not need to be "universally applicable" to be useful. Indeed, the very notion of "usefulness" implies some degree of pragmatism which implies some amount of imperfection and/or compromise. The aggregate score is probably in fact quite useful for its target audience. Suppose you're a naive consumer looking for some kind of step up camera, and you are looking at the bewildering array of consumer SLRs, superzooms, high end point and shoots, and mirrorless cameras. The single score measurement does provide a pretty good indicator of which camera is capable of better image quality. Even the single score will pretty quickly tell the consumer that there is a size / image quality / zoom tradeoff.
To me what seems to be driving the outrage here is that Canon sensors get lower DxO scores than Sony sensors. But the relative rankings here are pretty well deserved -- Canon gets trounced at base ISO. It's not even close. At high ISOs, sometimes the Canon sensor inches ahead but the gap is small. So while it's true that there are many shooting scenarios where the Canon sensor is equal or even slightly better than the Sony, if you had to honestly answer the question, who makes the better sensor
and had to give a straightforward answer without going into the nuances of use cases, could you say "Canon" with a straight face ?
But how many people look at the Measurements? I suspect it's much more common for people to just stop at the scores.
This is probably true, and if they are just looking at the scores, they are apparently not interested in digging any deeper than that.
Furthermore, DxO's scores are also reported by other sites, e.g. Snapsort, without reference to the underlying measurements. They report DR, for example, but there's no mention that it only applies at base ISO. That original DxO bias is propagated elsewhere.
I don't completely agree with this. The "high ISO score" already takes into account performance at higher ISOs. This score is a pretty good indicator of performance for those who do most of their shooting above base ISO. The dynamic range score is a pretty good indicator if someone is shooting at base ISO.