I guess it depends on what theory of diet you follow.
Carbs can be a bi controversial. Yes dogs can digest them and derive energy from them, they have actually evolved to be able to digest starch in ways that wild canids cannot. Carbs are an affordable source of energy (Kcals) and if you choose your carb source wisely you can get an extra nutritional punch (Like if you pick a sweet potato based food you get a nice dose of caratenoids)
However, there is a school of thought that carbs = sugar. And excess dietary sugar is bad bad bad news.
There is quite a bit of research out there on this topic. You can just go to scholar.google.com and type in carbohydrates + any chronic health condition you can imagine
and chances are that there has been research done that finds a link. Especially with the refined carbs. Notably, there is the carb and cancer link. High carb diets can be rather inflammatory and promote microbial flora imbalance.
Of, course, many dogs do well on higher carbs. I personally, prefer a lower carb diet for my dogs. The food I put in their dish is closer to 90% meat with the remainder made up of healthy dairy, fats, leafy greens and some fruit. I don't have a total ban on starches though, every so often I'll put a few spoon fulls of mashed sweet potato, or 1/2 a cup of brown rice in his dish. I've even been known to give him some pizza crust... but overall I do prefer a lower carb diet.
THK base products are nice, but for various reasons I personally would not use them as a staple - They are pretty carby, one has a LOT of flax, and they both use peas. For me THK products are more of "make thing easy for the dog sitter" or an "Oh crap I forgot to thaw anything for the dogs, let's just open a can of mackerel and add it to a premix" type of product.
If you are interested in using a premix, but want to feed a lower carb diet, Dr. Harvey has a new low carb premix.