Is the current Mueller investigation a new way to find things to hate about him?

Yes. I wouldn't call it a "new" thing though, as it's been a year and a half and everyone's getting very impatient. Maybe they don't even want to wrap up the Mueller probe, as it keeps Trump in legal molasses and heavily strains what he is able to get done in office -- for example, anything he even slightly does involving Russia is immediately off the table, lest he be accused of being a Russian puppet and create the public outrage needed to justify an immediate removal.

Cause crimes seem to be a fair reason to share some contempt for.

Oh, they sure do. I'm glad that those who are rooting for Mueller see it this way. Because crimes are indeed something worth taking a VERY hard look at. I guess time will tell.