Science certainly hasn't weighed in on favor of high protein diets or abandoning cardio unless you cherry pick specific smaller studies to get what you're looking for. On the other hand there are HUGE studies supporting cardio, both for weight loss and for health.
I've written about this many times before on HN:
According to the 32,000 person study in the American Journal of Clinical Nutrition (1999), "fit persons with any combination of smoking, elevated blood pressure, or elevated cholesterol level had lower adjusted death rates than low-fit persons with none of these characteristics". The same study found that aerobic fitness had a far more important impact on longevity than obesity did. Fantastic Voyage, Kurzweil and Grossman, Chapter 22.
Here's a report on a study that monitored over 100,000 people:
Paul Williams, Ph.D., author of the study, found that men who ran two or more marathons per year were 41 percent less likely to suffer from high blood pressure, 32 percent less likely to have high cholesterol, and 87 percent less likely to be diabetic than non-marathoners. Those who ran only one marathon every two to five years also had significantly lower risk for these conditions than non-marathoners. The benefits of running marathons were largely independent of total number of miles run per year by participants, indicating that isolated distance running bouts in preparation for marathons may have been effective in decreasing risk of disease. Even runners who didn't run marathons - those who included longer runs as part of their usual exercise routines - were less likely to have high blood pressure, diabetes, or high cholesterol. http://www.medicalnewstoday.com/articles/140104.php
Here's a different piece on how regular hour-long runs stimulate neurogenesis and memory improvements in middle aged humans:
http://www.dana.org/news/brainwork/detail.aspx?id=7374
Distance running is one of the most beneficial things you can do for yourself. Racing marathons can be reasonably low-risk with sufficient training, but it's the training that gives benefits.
In terms of life expectancy, endurance athletes such as marathoners and cross-country skiers live about 2 years longer than sprinters, 4 years longer than power lifters and 6 years longer than the general populace. (warning- small sample sized case study) http://www.mdconsult.com/das/citation/body/163630869-2/jorg=....
Recommended food for thought for those convinced that low-carb is the optimal diet: Why is it that both Atkins and Taubes got so fat on very low carb diets while Japanese people traditionally ate (and many still do eat) rice at every single mean, lunch, breakfast and dinner? Maybe a bunch of high protein eating redditors don't have all the answers.
http://www.thedailybeast.com/newsweek/2008/07/15/the-never-e...
http://www.paleopharm.com/what-if-gary-taubes-is-a-big-fat-l...
http://opinionator.blogs.nytimes.com/2012/03/16/no-surprise-...
My own personal experiences are largely irrelevant, but FWIW the leanest and fittest I ever was, I was getting nearly 80% of my calories from carbs. And the time in my life I gained the most, I was only getting closer to 20% of my calories from carbs. I can respect someone who encourages testing, a la Seth Roberts' "n=1 studies". I can't respect someone who puts up a few blog posts and claims to know more than the entire medical establishment. Americans are more into protein and more into weightlifting than any other nation I've ever seen. And while there are a number of muscled-bound guys strutting around, there are a whole lot more fat people buying into the same pop weight-loss ideologies.