Sounds like you've heard yet another case of people turning shades of grey into black and white.

The Euro specs that get a lot of attention on the Internet do seem to put more emphasis on performance under high temp, high stress conditions. Most American and Japanese oil specs
tend to be milder and focused more on emissions and fuel economy. But Euro brands do care about fuel economy, just as American and Japanese brands care about longevity and performance. This is about more vs. less, not all-or-nothing.
Keep in mind the cars' target audiences. Most of the European cars we see are German and built for high performance. Most of the American and Japanese cars we see are designed for people who just want to dawdle to work and back. The cars and the oil specs are designed accordingly.
And, of course, there are exceptions. Honda's HTO-06 spec is one of the toughest around, at least in terms of high temp deposit prevention. GM's long-drain specs are fairly serious, as well.
Hope that makes sense.