Can I prevent shorts from showing up for me?

You can create two Google accounts and parental control yourself. You can also use ublock or other browser addons, and of course, NewPipe. Youtube should have more settings for this, it's clearly going down the drain, but it's not like you can do nothing.

Honestly, it's one of the reasons I don't want to pay for Youtube Red, why would I pay for "no ads", when I still feel like I'm the product, because of my complete lack of control over the algorithm and user experience.