Let’s talk bike parking. Here, we have two examples of bike racks you would see in Portland, Oregon: the wavy line and the staple. You will notice that nearly every bike is parked perpendicular to the bike rack.
The reason that one should park perpendicular to the bike rack: other people. If we lived in a vast world with few people in it, then it would be fine to lock your bike parallel to the bike rack. But we do not. Bike racks get a lot of use, so you need to leave room for others.
This e-bike riders has not gotten the memo. By choosing to park their bike in this manner, they have denied another biker a spot on the rack. Because these bike racks are full, this is a particularly egregious gaffe.
If one wants to lock up both wheels, this can still be done. After my expensive back wheel was stolen (back in 1996) I started locking both wheels. I lock the expensive back wheel to the rack and lock the less expensive front wheel to my bike frame. I figure two locks are better than one, especially with my economical bicycle.