There are many, many Paleo recipes that call for canned tomatoes however most of them have sugar and stuff like calcium chloride. Why is this acceptable in the Paleo world?
Because every single time someone references an ingredient, they shouldn't have to specify you should use a high quality ingredient. Imagine how tedious recipes would be if it was "organic premium 100% grassfed 20% lean roughly ground chuck beef" or something, all the time instead of "ground beef."
It's acceptable because people have busy lives, and telling someone to chop or boil and peel 10 tomatoes can sometimes be overwhelming. Also, there are good, organic versions out there that are probably fine to consume.
Please note that tomatoes themselves have a lot of sugar in them. A single tomato might have 2-4g of sugar. A cup of chopped tomatoes, with nothing else added probably has close to 10g of sugar.
Also, Calcium chloride is just a cheap source of "salt" which helps to enhance the shelf life without adding sodium to the nutrition label. This is GRAS and maybe in the organic tomatoes too.
For me, I chop my own tomatoes because I mostly eat the ones I grow. The only thing that comes from a can is tomato paste.
I haven't seen a lot of tomatoes with sugar in them (unless you count the natural sugar on the nutrition label.). Calcium chloride is a Preservative, so something to be avoided but not totally verboten.
I use canned tomato occasionally because of the BPA issue.
I'm so used to substituting the best versions of everything, I hardly pay attention. And I avoid tomato from a can because of the BPA issue. You can find it in a jar or tube. Or just chop your own.
An excellent observation.
It's not acceptable by everyone. Certainly not by those who understand that the nutrient density loss due to modern methods of food production and distribution is extraordinary. A modern tomato from supermarkets is little more than a red water balloon these days.
Also, added sugar does not equate to the sugars found in the fruit. They are metabolically handled very, very differently. The same goes for salt and other additives.
However, it does come down to convenience, availability and economics. Try to make informed choices by increasing your knowledge.
I don't see why people even use canned tomatoes. Slicing and dicing 4-5 tomatoes takes 2 minutes you could save, but if you're already cooking, it's time you would otherwise spend waiting or doing something else related to cooking. Fresh tomatoes taste better, and are healthier, and don't come with BPA.
It's a no brainer.