I think there are enough small miners out there that it does make a difference to Bitmain. If not, they wouldn't continue to sell to us. Take a look at just about any pool, the split between large and small miners.
Kano has about 5-6 miners over 1ph in gear with about 13ph out of his total 26
Slush has about 30 miners over 1ph with about 130ph out his 210
That's just a couple of pools, but I would be willing to bet it holds just as true on Antpool or F2Pool.
That's still a lot of gear going to smaller miners.
And your data to back up that people want to underclock more than 140 PH worth of miners is.....
most of the reasons why you would undercock miners have already been stated..
the main reason is so people like me can run them off 110v power with only 1 20a outlet..