Why is Coinbase Not Adding New Currencies Right now?

investopedia.com:

Last week, when popular digital currency exchange Coinbase announced that it would not be updating its list of cryptocurrencies on offer at this point in time, ripple seemed to deflate. The value of XRP had soared at the end of the year, launching ripple into the number two spot for cryptocurrencies by market cap. On the news from Coinbase, though, XRP saw its value fall once again, dropping back below $3 per coin and causing the digital currency to slip into the third position on the list of largest virtual currencies by market cap. Why is it that Coinbase is not adding any new coins to its list of offerings at this time, particularly when interest in cryptocurrencies is continuing to build?

Coinbase announced its plans to not update its offerings in a blog post and Twitter update late last week. Currently, Coinbase offers transactions in bitcoin, litecoin, ethereum, and, as of mid-December of 2017, bitcoin cash. In its blog post explaining the decision, Coinbase pointed to last year's Digital Asset Framework announcement as one reason for the choice. As a result of that announcement, Coinbase's other exchange GDAX outlined criteria for adding new tokens and coins. In its blog post, cited in a report by Coindesk, Coinbase explained that «as of the date of this statement, we have made no decision to add additional assets to either GDAX or Coinbase. Any statement to the contrary is untrue and not authorized by the company.»

The Framework, announced in November of last year in advance of Coinbase's decision to add bitcoin cash, the exchange GDAX outlined a number of criteria which any digital currency must meet in order to be considered for inclusion. These include whether the listing would be legal under U.S. securities