Why should vegans not be able to make and eat the same recipes/foods as everyone else? There are countless reasons to replace individual ingredients vs inventing a whole new set of foods. People are increasingly into these products for some reason (myself included). Healthiness is another issue, but that's always going to be a concern for all lifestyles.

Because there's a market for it, simple as that.

There's also plenty of vegan products that don't directly emulate meat-based foods. Also some foods were always flexible in their ingredients, and expecting meat is just personal and cultural bias.