Linus Torvalds seems to think that in general, when compiling software, it's better to statically link libraries if you can, because very few shared libraries are actually version safe, and with dynamic linking, you're always adding complexity and exposing yourself to the risk that the system your software is going to get installed on won't have a compatible version of the libraries you need. In some cases, programmers may avoid specifying fixed version numbers because package managers such as Python's pip don't support having multiple versions of a given package installed at the same time, which could mean that the version of a package you request could clash with other software already installed on a given system.