Well, there are hundreds of exchanges and many more coming up, but not all exchanges are good. Only a few exchanges have got good reputation and the majority of investors have been trading there like Binance and Bittrex.
There is a difference between an investor and a trader. One can be both but those who are the big whales will either be an investor or a trader and not both at the same time. If someone is putting in their time to check out new projects to put their money into, they will have little time left to do technical analysis or check price charts to trade. Similarly those who are day trading would not want to get into a new project unless its pretty hyped up.
I dont understand why the question of exchanges is coming up here.
The fewer investors will decrease the market price. The market price is influenced by the volume, therefore we must convince the public to believe that bitcoin is very influential for the future.
You have no idea how many people are in the market so better not make an assumption like that.