Many people who decide to give up animal products in their diet will often call themselves vegan. They figure that the word vegan applies to some kind of diet and they might not be familiar with the terms "Whole Food Plant Based" or "Plant Based". Meanwhile, true ethical vegans get irritated because they believe being vegan is more than just not eating meat, but a complete avoidance of using any animal products beyond food... which means they will not wear fur, leather or use any products that were tested on animals.
Both sides have a point. How are plant based people supposed to know not to call themselves vegans when the word is on the supermarket shelves much like "gluten free" or other labels are. Restaurants will identify the food that contains no animal products as vegan. Plus, plant based isn't as common in people's vocabularies as the word vegan.
Ethical vegans are working hard to get their message out about the mistreatment and abuse of animals. They see people who just avoid meat but wear leather as hypocritical. I've seen many posts on Facebook from vegans who clearly get upset when someone calls themselves vegan when in fact the only thing that they are doing is not eating meat. They are still buying leather seats for their cars, buying products tested on animals, etc.
I'm not sure what solution there is when companies continue to market products as vegan. I think there needs to be more tolerance until the name "Plant Based" or another name catches on. And those that are Plant Based, understand why it might upset vegans if you are not concerned about the welfare of animals.
I'm very careful about not using the word vegan to describe my diet, although I could probably say I'm vegan. I am conscious about not using products that use animals in some way, something I never used to worry about before going plant based. I think it's hard to be plant based and not become more compassionate about animals.