Bitcoin can't validate the Counterparty invariants, thus Counterparty can't have decentralized consensus. Sorry you can't put smart contracts on the Bitcoin block chain. Rootstock is making a side-chain instead.
But the larger issue is scaling. And also of course the fact that Turing-complete scripts can blow up. To solve this, you need me. I've been working on the technological issues for 2 - 3 years.
A side chain is the proper way to do this, and it can be merged mined with the main chain. Scaling as we both know is a very serious issue so one has to start with a base coin that can scale on the main chain properly even before adding smart contracts. Then address the scaling issues of the smart contracts themselves.
Side-chains are insecure:
https://bitcoinmagazine.com/articles/side-chains-challenges-potential-1397614121
https://news.ycombinator.com/item?id=7613520
http://www.rootstock.io/blog/sidechains-drivechains-and-rsk-2-way-peg-design
My expectation is that Blockstream (+ the Chinese mining cartel) are going to either outright break or centralize the mining/control of Bitcoin. We need to be ready with something that works correctly for when they do.