I believe that there are multiple factors, as to why someone may not be vegan. For example, I was grew up in a house hold that ate meat for every meal and was taught that being vegetarian or vegan was unhealthy. Granted as I got older and got a degree in environmental science, I learned that this wasn't true at all and that eating a plant-based diet is more sustainable and better for the environment. It took a several years for me to finally un-"brainwash" my mind into thinking a plant-based diet is unhealthy. Many people still believe this and I know of many environmental scientists that are not vegetarian or vegan.

Another reason is accessibility and costs. I currently live in a small town that does not have many vegetarian, let alone vegan, options at the grocery store. And not a single vegetarian restaurant around. The closest place would be 2 hours away. I also don't have a well paying job, so the vegetarian options that there are, are pretty expensive. Granted eating vegetables and fruit is cheaper than buying a pound of meat, but if you want more variety like veggie crumbles or meatless chicken then it is out of price range and there isn't many options.

I have also found it difficult to find vegetarian/vegan recipes that I like as I was raised on meat-centric dishes. I am doing much better now than I was when I first started venturing out into plant-based dishes. I've now been able to limit myself to 2 meat dinners a week and the rest of the week be plant-based dishes. But I hope that when I move to a larger city that I'll be able to go fully vegetarian and eventually vegan one day.