Can you summarize the reasons you think that? not quarreling here, just genuinely interested. i can't see any "obvious" reason.
MSC is based on an idea that you can stuff arbitrary information into a bitcoin transaction. However, it does not leverage Bitcoin's main capability, that is, the ability to prevent double spending. You can use any protocol (http, smtp) to enable MSC. The use of Bitcoin's network is more hype than substance.
That’s an opinion, in my opinion, not an obvious “flaw” that can be logically argued. For your premise, that “Bitcoin’s main capability” is in its “ability to prevent double spending,” you are correct, MSC does not leverage this capability yet. But that doesn’t mean that it won’t in the future.
We’re just beginning to scratch the surface of what effects “conditionality” can have on trustless transactions on an open, secure ledger. Time will tell, but more will come.
If you’ve got any ideas, let us know. We strongly believe that our critics will be our strongest influence in making the Master Protocol become more advanced with more useful features. The more masterminds the better, so please continue providing your feedback, and consider contributing to the effort by offering your criticisms in an actionable way.
Thanks,
Craig