That blog post doesn't mention the weaknesses of Cryptonote/RingCT which I have explained numerous time. I posted a comment to that blog and it still hasn't appeared. Thus so far, I think that blog is a monero shilling vehicle and not objective.
I'm not sure it is a shilling vehicle, though it might be. Zcash appears to have paid PR going on which gets it a lot of coverage in places like Wired (along with grossly unethical pumping from bitcoin.com, owned by Roger Ver, an investor in Zcash), while Monero does not. Thus it is quite plausible that people might just want to respond to the aggressive Zcash shilling and point out some less rosy perspectives on it that you certainly won't hear from the paid PR and pumpers.