That is status quo for BC ferries so you didn't experience anything too unusual. I ride the ferries a lot and try to get in the boarding que early or walk a little faster than the others (but not in a goofy way) so I get a good pick of leaning spots.

Sometimes there are bike racks just back a bit amidships near where the walk on baggage cars park but I actually prefer the wall as you can lean it pretty good. Just dawdle and wait until someone else comes so you can be present and help them lean their bike against yours if it's busy.. This double stacking usually only occurs at peak tourist season, otherwise there is enough room for everyone to single lean.