Since each token would have their own reward pool, there would be less pressure on the STEEM reward pool. As such, people who focus only on the STEEM reward pool will indirectly benefit from the existence of many other tokens.
This is because payouts in those other tokens won't crowd into each other. They would be segmented.
I see what you're saying about high-demand tokens. Let's imagine that the community creates a CN Community Token for the Chinese community.
Let's also imagine that CN token is incredibly popular and it's the second largest token next to STEEM itself. So poloniex opens a trading pair for BTC/CN.
The interesting thing about that situation is that it creates an arbitrage opportunity. People with a lot of STEEM might buy CN internally so they can sell it on poloniex, creating demand for CN. If there's enough volume, it would cycle back and forth, rather than just go one way perpetually.
Meaning, once the pressure to arbitrage CN in one direction finds equilibrium, it will go in the other direction for a while, creating demand for STEEM.
The equilibrum you speak of won't protect steem power holders as the CN community will take a lot of market share away from steem still. Many projects will develop around this token and thus it will be directly competing with steem.
@ned and the devs at steemit @vandeberg,etc..need to make sure that these tokens can only be bought and sold with steem. Maybe a mecanism like rootstock where you can exchange RSK for BTC and back would guarantee that these tokens are only redeemable for STEEM and that you need to buy STEEM in order to acquire them.
One thing that many say is that steem has the community and you can't copy a community, this is true however one reason why this community is so powerful is that we all use the same token and all want it to suceed, implementing a token for each sub communities could turn out to be very divisive if this tokens doesn't directly benefit steem power holders.