please explain why you dont like middle ground
A few reasons.
1. Scoots (ALL SCOOTS) have poor suspension that is usually not fully adjustable (3 way front and rear).
That is just a mid-impact problem with 125-300 cc scoots, but with 400+ cc scoots that can reach 160-180 km/h this can be a real problem and, in my own opinion, could be quite dangerous.
2. I do not like 500-600 cc bikes because they are simply too slow, especially for riding two up. Furthermore, these bikes have very narrow seats and they are not comfortable for long rides. They usually develop their power highly and need to be revved up.
3. Big scoots are usually very expensive, and I would rather buy a bike. Furthermore, small bikes are usually too quite expensive, and I would rather invest 20 % more money and buy something I would be satisified with.
4. 500-600 cc bikes very often have poor brakes (just one disc in the front and sometimes even drum in the rear).
5. The price of big scoots and the fact they consume as much fuel as a small car and often more than a big motorcycle renders them useless (at least to me).
6. Big scoots usually have small tires and they are less manoeuvrable thank big bikes; big scoots are very heavy, typically 500 cc scoot weighs as much as 1200-1300 cc big bore bike and 15-20 % more than similar sports bike or sports touring.
Generally, for the price of new 600 cc scoot from Yamaha or Honda you can get 750-1200 cc big bore bike.
These are just some of the reasons I can think of right now.