the so-called MIT licenses (there's more than one) are fine Free Software licenses, but which license is best depends mostly on what you're trying to accomplish. if you don't care at all about the code and won't mind if it's integrated even into software that ends up being used against you, to control you or to restrain you, no change is called for. but if you'd prefer to contribute to the commons and also to avoid its over-exploitation, a copyleft license would likely serve those goals better. if you haven't derived any of the code from third parties, or even if you have and it's all under such lax permissive licenses, you can still relicense it under e.g. the GNU GPL
see also https://www.gnu.org/philosophy/pragmatic.html
thanks for your contribution to the community