I’ll acknowledge that Michael broke laws while (the thoroughly vituperable) Rowling has not.
But I don’t hold that to be an arbiter of morality.

For me it comes down more to how they seem to view other living beings.
Michael has no clear evidence of deliberate, knowing, harm. Yes, he should’ve known better, and without being in his head I can’t know for sure… But it seems to be plausible.

Meanwhile J. K. (I feel more comfortable with a gender neutral name even now everyone knows me but gender bending is right out) Rowling has made it clear that she doesn’t value trans-people as much as cos-people and is willing to set up conditions which greatly increase sexual assault against trans-women if it might only slightly reduce the threat of sexual assault against a single cos-woman, and does not find issue with cooperating with actual neo-nazis and crypto fascists who have strong misogynistic and homophobic stances on anti-trans issues - despite claiming she doesn’t want to harm those groups. She is choosing to value particular groups and ignore, and create, suffering for others she seems abhuman. (And yes she has a tragic back-story of an abusive husband and marital rape, which she says is why she must ensure gender is immutable.)

But - evil and harm can’t be compared and the totally different natures of what they do make comparison even more pointless.
If you continue to enjoy either of their work (or that of any other harmful person, be it Marquis de Sade, H. P. Lovecraft, or whomever) more power to you - but just try your best not to fund She Who Shall Not be Named’s warchest.