The reason that there's a demand for a plant-based "burger" is due to its lower impact on the environment. People don't seem to realize how much water and energy cattle ranches use or the amount of emissions they give off. In comparison, the production of Beyond Burgers cuts water use by 99%, cuts energy use by almost half, and cuts greenhouse gas emissions by 90%.
As for the taste... It's definitely more meaty-tasting and has a better mouth-feel than an old-fashioned veggie burger. That's probably due to the salt and fat content which are similar or higher than real beef patties. However, it has benefits such as lower cholesterol and higher fibre.
Anyway, I think that people should try the Beyond meat (there's also plant-based chicken) at least once before making a judgement. Personally, I prefer real beef and will choose it over Beyond meat every time. But, I can see why it's popular with people who are worried about the environment or animal welfare.
Note: I grew up on a ranch. It's a great lifestyle, but even I'll admit that it's not really as natural as most people think it is.