Bertram Wolfe in Henry VI points out that the attainders included entailed lands. This was, he says 'in gross violation of the currently accepted practice of English common law that entails were sacrosanct, even against treason, a convention ominously last flouted by the tyrannous Richard II in 1398.'
Well, it was 1397, actually. And, like many critics of Richard II, Wolfe ignores the fact that the proceedings of 1397 deliberately mirrored the harsh treatment of Richard's friends by the Appellants in 1388. So it was the Appellants who were 'tyrannous'.
Anyway, the seizure of entailed lands was harsh. But the treatment of the womenfolk was generous and the Yorkist lords only had to 'humbly submit' to be guaranteed pardon. So I'll leave it to you out there to decide for yourself whether the treatment was 'tyrannous' or not.