After thinking about it a little more, I put this to the people who claim Eureka is not 'casual' content and that we've received other forms of 'causal' content:

If you take just Eureka maps/zones into account, Eureka seems like a mini-expansion's worth of maps/zones .

The additions to existing 'casual' content like Doman Mahjong, new treasure map,etc are not similar in scale or in ability to keep 'casual' players engaged for a sustained period of time.

If we are going by the participation rates for Eureka as offered by the Lucky Bancho census, it makes more sense for SE to develop 'casual' content similar in scale to Eureka which would serve a wider audience.

By all means,keep Eureka but please provide similar content for 'casuals'.