>Shouldn't a nutrition/meal replacement startup strive for more than "well, you're eating shit anyway, why not buy our almost entirely untested and unregulated shit!"

Sure, but I think the size of its success or failure for each person should be measured against their health if they were to go on eating their regular diet, not some hypothesized perfect diet.

The alternative to me seems a little like saying condoms will always be a terrible method of STI prevention because their prevention rate is less than 100%, and you can achieve 100% prevention with strict abstinence. For people who can't or won't practice strict abstinence, that comparison doesn't seem very useful.