Why do old exchanges continue to close such as cryptopia, coinexchange and the new nova exchange, what is the reason for the lack of users or teams that are no longer solid?
Cryptopia got hacked. So that one's easy.
Coinexchange simply never attained enough popularity to be profitable. They have over 500 markets listed and not even 30 BTC daily trading volume. It wasn't sustainable so they decided to fold......unsurprising in this saturated market.
With Nova Exchange, I'm not sure. I always thought them closing down and reopening (alienating their entire user base) was a ridiculously stupid business move. As I expected they never recovered. The closure could just be a matter of business as with Coinexchange. Or it could be more nefarious as some people allege:
This was a long orchestrated scam. Now they not only have your coins, the fees for re-listing from already burnt Cryptopia victims, and the KYC data.