AFAIK there is no hash for ternary, so you would have to roll your own crypto, so that isn't a valid criticism in and of itself. Now if you want to criticize them for not getting an outside group (they have highly qualified mathematicians and access to a super computer) to vet it, that's a valid criticism--though we'll see how valid when cybercrypt finishes their research. Though as an investor, I was only interested in how they took the threat seriously (they removed it) despite not getting the data they wanted from DCI.
As for making your own seed, Bitcoin didn't have a seed generator in early wallets, so why did they get a pass when their goal was P2P? The IOTA team wasn't even going to have a human wallet (wish they had stuck to that), but made it very clear that the wallet they did issue would be bare bones and users should understand how it works (they obviously didn't), but no one was complaining until something bad happened, so it seems like rehashing a pain point rather than an "I told you so."