Hhmm... I think to limit the number of exchanges that must be had, I cannot answer. As far as I know, the exchange was made to sell tokens. Sometimes there is a bounty project that has a token in exchange which is not yet available to me. Automatically I have to register at the exchange.
There is a problem, we can`t have limits. New bounties are listed on new exchanges, or IEO is on a new exchange, if we wish
to participate in bounty or to invest we need to register on that new exchange.
I assume that big exchanges ask for big fees, while new ones are more opened for new projects even for free. There is not any
other explanation.
Only way to skip this step, registering on new exchanges is to carefully choose where to participate. But in that way you can miss
some good project.