BTW in some sense, BTC is already inferior to many other newer blockchains
Factom is really a BTC/ETH app and inherits from the security of those 2 blockchains.
XEM would be better IF its security was equivalent to BTC which it has no chance.
I rearranged your post a little to analyze it. Can you clarify your argument as to why NEM isn't as secure as BTC and which alts you consider superior to BTC?
I think you should re-read his post, the answer is like literally "between the lines". As for alts superior to BTC, I guess you could take a look at XMR for example:
1. Faster
2. Truly anonymous
3. Mining is not centralized because the algorithm can't be implemented into ASICs simply