Left hand is a small creek, with a small drainage area, and the high country snowpack to the west of the canyon near the continental divide gets mostly captured by boulder creek and SSV. Left hand also has a reservoir at the headwaters. This means that left hand flow is usually low, to dog low, to bone dry. Clear creek could be running a solid medium, and left hand could still be a piss trickle. Left hand's primary problem, is flow, it never seems to get enough to make it worth it for most, and when it does have water, the other runs in the area usually have more.
Left hand also does not have an internet gauge, so the level is checked visually. If it does happen to rain enough for left hand to run at a good level (rare), you probably won't know it unless you live right there.
Boaters who live right near left hand probably run it because its right in their backyard (I would too if it were in my backyard), but most boaters would have to drive by runs with way better flows and rapids on their way to left hand, so why bother? It that sense, its not usually worth it as compared to other local options of similar difficulty.