I agree with Anonymouse that there is a risk that the player base might not be large enough to support lots of games online simultaneously. However, as we can see, there aren't all that many online Dreamcast players these days period. There are 235 players in total according to http://dreamcast.online/now/
, and though that doesn't count everyone, it is a good approximation.
That being said, getting enough players is why we organize game nights - to focus the player base at a particular game. As long as the game nights continue, there should be enough people playing online. Hopefully one day we will have enough active online players that many different online games can be played any hour of any day of the week.
Besides, PSO all by itself gets monotonous.