That's not saying the lights "that won't use them" are somehow ethically/morally/engineering-wise superior. "Don't" is probably a better word to use than "won't". Truth be told, those lights suffer from an inferior electrical design. They may be good lights, but they are older designs and failed to keep up with recent trends. Much like what happened to Maglite.

This is one reason why I bought both a 4Sevens and an Olight over a Fenix. Fenix makes good lights, but they suffer in the design department in that they cannot use the higher voltage cells. That is not a plus for them. That is a minus. 4Sevens and Olight (at least the specific models I bought) don't suffer from that deficiency.

So definitely check out the light you are considering purchasing for what voltages it will accept (and build quality, and other things too). Simply buying a well-known brand name is not good enough anymore.