A few reasons I think: - inexpensive - delicious - stacks well (can serve at scale) - not messy, even without plates Nearly everyone likes pizza, and there ar

A few reasons I think: - inexpensive - delicious - stacks well (can serve at scale) - not messy, even without plates Nearly everyone likes pizza, and there are lots of varieties for various tastes. At my work, we've tried various foods, but we always come back to pizza because it's so universally liked and so convenient.