With any amplified signal, if you don't have the power/headroom necessary - even at what is basically a preamp stage - you get all of that farty/splatty/ugly distortion sort of stuff.
So long story short - w/an OD pedal, you can have more bass at low gain, or you must reduce the bass at higher gain. The only exception would be if you had the power/headroom to pass it on, and we are limited to just 9 volts for our little "preamplifiers." Actually, the OD-3 cuts this down to 8 volts.
Along with something like the SD-1 or TS allowing it to "cut thru" or stay "tight," you don't experience any of these issues when you max the drive/gain.
With a mass produced pedal, it is not uncommon for there to be what IMO amounts to an unusable portion of the control sweep. With drive boxes, this tends to be the gain/drive knob. With a fuzz or distortion, it can be something on purpose or expected, but not so much the case with OD.
...So Boss could have done one of two things - either cut the bass so that it might have sounded anemic at lower gain settings but great when you cranked it up, or effectively cut the gain range down to about a half of what it is. If they killed the bass, I'd argue that the OD-3 would be just another variation on the SD-1 or a similar type of OD. It's not to say that it would be a bad design, but Boss had already made such a product. So - option 2 - limit the gain range - is something they didn't want to resort to. There's clearly a percentage of users with mass produced gear who are going to max out some controls even if the sonic results are not stellar.
...I mean - I hear folks refer all the time how with some pedals that if you dime the gain it turns into a fuzz. That includes the BD-2! And I personally don't know why Boss would do that, until I consider that they are trying to appeal to the biggest percentage of players as possible. So that includes all of those folks who dime the gain in spite of what they hear.