That's a particularly ridiculous statistic. It's not all that difficult to find a technical review of a power supply if you want one. Most people don't, they're looking for the words "quiet" and "modular". There's a considerable difference between wrong and irrelevant, very few of the reviews their article is condemning are wrong for the simple reason that they don't say anything testable.
If you buy from one of the high end brands they actually quote specifications and adhere to them. 7 year warranties and rating their supplies at 50 degrees ambient is a good sign as well. 6 months warranty and not actually specifying operating temperature is a bad sign. If you buy based on the cheapest per W you deserve everything that's coming to you.
edit:
I'm not completely convinced the author knew what he was talking about either. That or he is deliberately misleading. Indeed a multimeter power won't tell you a great deal, but it's fine for checking if the rails are within the 5% range the atx spec requires. It'll also show the rail drooping with load, and will demonstrate cross loading with no problems either.
Motherboards are designed to run on dirty power; it'll never be a perfect 12V when there's several things drawing various amounts of current from it. It has to assume a psu which is barely atx compliant to avoid huge numbers of returns. Obsessing over ripple is largely a waste of time as a result, it may be worth a couple of mhz, but then again it might not be.
"99%" of reviews are like that because it's all people want to know, and probably all they need to know. I don't think insisting every review include a tear down of the supply and discussion of the component choices would lead to fewer people buying 1200W supplies for £30, it'll just alienate people further.