Nowhere do they recommend that you replace every single meal with Soylent and the creator stated many times throughout his many blog posts that he continued to eat normal meals whenever he felt like eating normal meals. This is in contrast to something like the movie Fat Sick and Nearly Dead (http://www.fatsickandnearlydead.com/) which actually does recommend drinking veggie shakes exclusively for every meal for 90 days.
That to me doesn't sound like a recommendation to actually replace every single meal for that month. Rather, it's a unit of measurement that provides better context than simply giving the number of kilograms of powder you'll be receiving. Even so, I don't think it would be harmful to do it for an entire month anyways, and I doubt very many people will be that hardcore about it. It will work perfectly as an occasional meal replacement for busy geeks on the go. Attacking the extreme case is attacking the straw man, IMO.
