Most of the best pens refills are made by japanese companies (eg. Pilot, Zebra, Uni-ball, etc.) and Parker style is nonexistant in that country. If you look at any "top XX best pens" lists online, the vast majority is not avaible in Parker. And when they are, they usually have fewer color and size options.

It's very disapointing to see brand new nice pen designs that only support Parker refills.