For the record...horseradish and wasabi are completely different plants/flavors. Most of what you'll find in the US is horseradish (which I also like), but green dyed horseradish is most definitely NOT wasabi (despite what anyone or any packaging says...).
Most of this is due to how cheap and common horseradish is compared to wasabi. Wasabi is considerably harder to grow and both the leaves and root can be used for food, medicine, and such. Horseradish is pervasive (like a weed), and sure, lol...try eating those leaves and see how it goes.
Horseradish
Wasabi