I don't do the online argument thing, so I've deleted my responses to the user to whom you expressed confusion, but I've edited my original post to hopefully be more clear and to address this fine point they're making (that excess protein only turns into carbs when the body's demands require it).
Basically, what the linked nutritionist's blog is pointing out is that the process of protein being altered into carbs only happens when the body demands more for vital processes. I didn't discuss all of this because if you are in a calorie-restricted and severely carbohydrate-restricted diet, then the body is going to demand more carbs and it will get it somewhere. Every keto diet book I've read discusses this at length and dieters want this to come from is ketosis (burning of body fat) - not from excess protein (or excess fat), so dieticians came up with the 5% carbs, 70% fat, and 25% protein goals. None of this is exact as our bodies work differently and have different needs based on various body processes that may change from day-to-day, but these are goals for a reason.
It is difficult to hit these targets though and I often will have "too much" protein, but at least it is within the realm of reason. Before I started finding ways to add fat to my diet, I'd sometimes have half the fat I should have and twice the protein. Also, I'm never hungry now that I've increased my fat in-take and lowered my protein while still staying within calorie restrictions.
Clearly, there are some people that feel strongly about this subject, and passion is great and I'm certainly not infallible - but I get upset when people are ugly or hateful.