TBH, it's valid criticism and definitely stuff you should think about as a LD and env artist. Looking at it from the outside, some design decisions that were made on a fast evolving project can seem strange or non-obvious. Things you wouldn't do when working on something yourself or on your own time. Art wise, it may seem that doing a vista takes more time than doing a road, but under gameplay constraints a vista is much much easier because it fully blocks off the gameplay space and solves a lot of potential issues on a game that has characters that can fly or climb up walls.
Route66 did actually at some point make more sense layout wise, as the warehouse started out as a tunnel. with another open end at the final point. You can still see this in Nick Carver's concept art here:
This was the original end of the map, and I even had a vista blocked out for it, with a road going off into the distance. However, the map had gameplay problems and design felt the player spawn should be behind the capture point, so we changed that part. At this point we were close to the deadline so it wasn't possible to go back and change another part of the map to fix it up. Going back and changing something that is already art-finished is a big cost in game dev, especially if it potentially opens up a bunch of other issues that will then need more play testing. At this point, people already liked the map, and ultimately gameplay comes first so you can only do so much as an artist trying to make things make sense.
There's a story like this for pretty much every overwatch map