It kind of is... for inexperienced riders.

Some of us that ride a bit more have the gear inches burned into our brains for each ring/cog and know how they overlap (so we know when and how to shift, to keep momentum and efficiency at their peak), but for someone just getting on a bike, they don't have that kind of knowledge.

The short/mid/long discussion has more to do with capacity of each of the front rings than it does with overall range. Just because there is a theoretical 27 speeds doesn't mean that all combinations are possible (or even efficient).