This is one thing that bugged me. I started to dislike par 3s as they tended to be the holes where I don't get shots in Stableford. But I've had to change my mindset. I now try and ignore which shots I get where and just think of it as needing to get 4 pars plus another par for every double - and which holes you get them on doesn't particularly matter because it all adds up the same in the end. 1 point on a par 3 and 3 points somewhere else is no worse than getting 2 and 2.
It is funny. Our SIs are based upon difficulty
Our par 3s SIs are 3, 5, 7 and 14.