diversify into what exactly? The entire cryptocurrency ecosystem seems highly correlated. Take a look at coinmarketcap.com, the charts are essentially the same for nearly all the listed coins.
Diversify in the trading fees that come from listing other coins.
They're trying to take more slices of a shrinking pie, hoping to capture enough of the long-term cryptocurrency market share to justify their current size and valuation. It's also a really good time to muscle-out some of the weaker players.
They want you to have as many Ponzi schemes as possible to invest in.