History sort of gets in the way of these kinds of opinions. In order for Henry and Catherine to wed (a thing Henry was not origianlly in favor of), a dispensation was required to remove the impediment of affinity between them, arising from the fact they were in-laws. At the time, impediments of affinity went out at least to the 7th (IIRC) degree, and Henry and Catherine faced a relationship in the first degree. So, Julius issued a (poorly worded) dispensation. Poorly worded in that it did not specifically dispense from the impediment of the justice of public honesty, as was required if Arthur’s and Catherine’s marriage was not consummated. That it was not, is, of course, what Catherine always claimed, and it was probably true. Which left the impediment of the justice of public honesty undispensed. Such an impediment was certainly a diriment one, but it remained undispensed, even so.
Henry never took that approach. From the beginning, he rested his causa on the Levitical Prohibition, which he came to believe was ultra vires, beyond the power of the Pope to dispense. There are such impediments; whether that was one the Church has held differing opinions on. But even Campeggio said Henry’s point was a sincere conviction.
On the larger historical point, decrees of nullity were issued daily, on the flimsiest of causa, to make and break dynastic marriages. Henry’s older sister received two, the two husbands of his younger sister received 3 between them. It was how the world worked, then. And, politics being what it was, what Charles did was how the world worked, too.
And the issue of confiscation of Church property came years after he sought his decree of nullity. Which he fully expected to get. It was how the system worked.
I really suggest some historical reading on the times. Scarisbrick is an excellent start.
GKC