The number by itself is fairly useless, but as a standard to compare bicycle gearing and wheel diameter combos between different set ups, it is useful.
If you can get everyone to agree on, and start listing a different standard that makes more sense, go ahead.
Sheldon Brown had some thoughts on the matter...I'll let you read his words rather than try and explain it.
Gain Ratios-- A New Way to Designate Bicycle Gears