This is an interesting comparison. I agree with a lot of it, because I can see the similarities. If you look at Splinterlands, there is a game that was created to also use SPL assets, it is called Splinterforge. It is a separate game, but you can still use the SPL cards to play. They are eventually adding more features to their game, and possibly other assets, but I think it is currently a good example of how different games/communities can still interact with each other.
Putting it back into hive, it would be nice if communities can coordinate with each other and work together. Similar to how SPL needs more new players, communities also need more members to thrive. One community doesn't need to be on its own, they can do things together. The /beer and /weekendexperiences can organize an event, or Leo and Ecency can plan something out.
I have never looked into Splinterforge, but I like the idea. This is what can happen in the future too, where people who "own their assets" will be able to utilize them outside of the direct ecosystem. Might be interesting. Perhaps Land expansion could have been a separate company for example.
The problem with Splinterlands needing more new players, is that they are cutting out the community interaction aspect. If people are focusing only on ROI, they are essentially cutting out the possibility to attract new players because price to compete is too high. What is the point of buying cards when you can't compete with the bots? Where is the fun for a new player, and there isn't even a community built to really discuss these things.