[lyime]

It's not really a problem per say. It's just taste really. There are multiple good options for managing ruby versions and environments. (as well as other languages like Phython, see pyenv). I don't necessarily switch to ruby versions between projects or with frequency. That being said, ruby is in active development and with new versions there are many improvements to performance and security. So developers like to try the latest and test out their apps, libraries and frameworks.