It is really hard to know what to make of this because there is no information on rates of problems, no numerical or statistical comparisons. The fact that a problem isn't covered by a warranty after 50,000 miles is not unusual, but they make a big deal of it. I also note that as IIRC Consumers Reports has found the Hummer to be horribly unreliable - possibly the worst of all, and yet no mention of Hummers on this list at all. I suspect Prius owners are more inclined to BLOG than Hummer owners?

If you Google for prius reliability and go through the sites, they are consistently found among the very most reliable (including used 2001 models). I agree we need to look at how they age, but this really doesn't give much to go on.