The only reason the Mac's are 6 point is that they have to be for the "edge" style of wrenches.
They use those raised lines on the flats of a 6 point to dig into the sides of the bolts so obviously it has to be a 6 point design.
It is an idea that is similar to what Snap On uses for there flank drive plus open end wrenches.
I know the Mac "edge" sockets are made in Taiwan and I believe the wrenches are also.
As for why there aren't more 6 point wrenches available, that is because there is no need for them .
The 12 points with the " flank drive " style of box end work fine .
There are no great advantages to 6 points and in fact there are some significant disadvantages.
The 6 points are harder to get on a bolt and of course they would not work on 12 point bolts either.
There are a number of companies that offer a spline style box though ,which works similar to a "flank drive" 12 point.
The Blue Points are actually 12 point, not 6 point, and they will all work on 12 point fasteners.
They are 12 point all the way through until you get to the very outside edge of the top of the box .
At this point 6 of the 12 points are covered by a thin bit of metal making it look like a 6 point but it is actually a 12 point box.
These 6 points that are blocked off make a "cap" to prevent the bolt from slipping through the box end.
It is a nice feature to keep nuts and bolts from slipping through ,and you busting your knuckles.
If you put it on a 12 point bolt it wont slip through as there are only 6 open points on the very outside edge .
If you put it on a 6 point bolt you can either align it with the 6 closed off points so it wont slip through, or move it over 1 point and then the bolt could slip through the box end.