That reason crossed my mind too. But on second thought, does it really make sense? Current RouterOS already works with VMware. And if you buy one licence, there's nothing except your honesty preventing you from making a thousand clones with it. What would change if RouterOS supported virtualization a little better? Well, people would tend to use it more, obviously. Both paying and non-paying ones. Which still sounds like MikroTik's victory to me.
People who quote full posts should be spanked with ethernet cable. Some exceptions for multi-topic threads may apply. Not intended as incentive for masochists.