A comment to the lefties, they probably didn't support a left side clip for this design because liner/frame locks aren't ambidextrous. Granted, that's only an issue for closing the knife one-handed, but that may be the reason.
newscoutYep, the Kershaw Cryo is one such example. It has holes to position the clip for tip up or tip down, left or right side carry.
I think it often comes down to the designer choosing not to simply because they don't want the extra holes in their design.
I'm a lefty btw. I prefer the knife to be in my right pocket because I keep my phone in the left. I open the knife right handed and switch hands when I need to have more control over the blade.