I'm glad you liked the article.
This is just my personal opinion, but I would say Dan chose to launch the EOS token on the Ethereum network because for now it provides the greatest access to liquidity.
Recently, bitspark.io launched their Zephyr Token ITO on the BitShares network and so far they have raised ~450K EUR according to this site. https://bnktothefuture.com/pitches/zephyr (There's more than 1 day left to participate)
You can find more about the Zephyr token ITO right here. https://zephyr.bitspark.io/