...and refrained from adding lots of altcoins like most other exchanges did.
I'm struggling to understand if it is a good thing or not.
I think it is possible to argue both positions.
Many altcoin additions to an exchange can be a good thing, because:
-they attract more users
-they offer more profit opportunities due to more available trading pairs
-they increase the profits of the exchange, because of more trades, which equates to more income in trading fees
However, many altcoin additions to an exchange can also be a bad thing, because:
-they often lack real trading volume and therefore are prone to market manipulation
-they clutter the user interface, which makes for a less pleasant trading experience
-they cause unnecessary server load, which decreases the reliability of the platform
for traders of the high volume currency pairs like BTC as well
To sum up, I´m strongly inclined to say that the approach of an exchange like Bitstamp
is superior to the approach by Kraken, Binance and Bittrex that add nearly every shitcoin
under the sun.