It depends how you define a scam.
An escrow isn't an escrow unless it is a third party, by definition.
That's fact.
You can Caveat Emptor, you can Bitcoin is Different, you can whatever, but that is a fact. A trading counterparty that pretends, thru an alias, to also be a third party escrow, is a liar indulging in deception for their own benefit.

If one party withholds information relevant to a financial transaction so that they benefit and the counterparty doesn't, is that a scam?
If one party lies by omission, offering to use an "escrow" which is not an escrow at all because it is them in disguise, is that a scam?

You could probably answer no, they aren't scams because nobody lost anything.

Is the attitude necessary to not only behave like that, but to also continually attempt to justify doing it when caught out, indicative of anything?
Yes it is.
Would I trust with someone with that attitude?
Would I fuck.
I'd count my fingers after shaking hands with them.