I hear what was said earlier about higher being better, but really this only applies to specific characteristics and is not always appropriate
Somewhat ironically, a higher score in golf does not mean better (A higher price does not always mean better)
The value surely relates to the thing which it it is describing and I,like most people, assume that speed really does mean speed !!
Rather than using a silly numbering system they should
(a) not have used the word speed !
and/or (b) actually given the speed value a real meaning e.g. how many screen/pixel units per second.
That way you would never get a speed below 0 , not matter how slow a club which you bring out....
They could, of course easily change it, if they could be bothered.
In the meantime , as was stated earlier, at least a warning to indicate the relative meaning of the value would be useful. Or how about a small colored flag next to the value e.g. green for less , sorry more than 4 , red for less than 3 ,etc...
Once again I am, or course, going on the general consensus that a slower meter speed is a good thing...