ohai should be more efficient when only displaying single attributes

When I run Ohai and return all attributes, it takes about 2 seconds:

$ time ohai > /dev/null

real    0m2.061s
user    0m1.540s
sys     0m0.710s

It ought to take much less time to calculate the json for only a single attribute, but it doesn't:

$ time ohai filesystem > /dev/null
real    0m2.016s
user    0m1.580s
sys     0m0.620s

It appears as if Ohai is executing all code and then filtering it down to only display the requested attribute. If this is the case, shouldn't it be possible to avoid executing code for unwanted attributes, thus speeding up Ohai in this case?