In their attempt to make a shoddy substitute for meat dishes, they completely butcher the innate capabilities of the vegetables.
I know that sounds a bit snooty, but western cuisines simply do not lend themselves well to vegetarian ingredients.
India is obviously the most familiar with good veg food, but most cuisines in Asia have good vegetarian offerings. Everything from China, Thailand, Iran, Lebanon and even Eastern Africa have some if not many great veg offerings.
Any cuisine that is based around spices (not necessarily the hot ones, but spice in general) is much better suited to vegetarian ingredients.
What we need is for people to become slightly adventurous in the way they eat, and stop living in their food bubbles.