66/34 is 2:1 or exactly the same as GPON (2.4 down, 1.2 up). We sell 1000 symmetrical on that GPON and the customers are happy. You would have much less oversubscription with 100/100 on a 1.2 Gbps wireless with 66:34 down/up ratio, than we are doing with GPON and 1000/1000. We are also doing 128 customers on a single OLT port.
Oh, well that might be the difference right there.
Many wisps generally tolerate a much lower oversubscription ratio. They want their customers to always get 25Mb/s when they buy a 25Mb/s plan. There is none of this 'up to 25Mb/s' that some providers sell.
Most WISPs could easily sell a plan where the 'up to' speed was similar to fiber. But then they would have to deal with angry customers who are whining that they aren't getting their 1Gb/s during peak hours.
BTW, I don't think we've ever built a fiber network with over a 1:32 ratio for this reason...