From Buzz's M&G all the way to the Northern end of Speedway, the Big Blue Box is practically invisible from the ground level. The TTA and Speedway landscaping, and the ride's canopy pretty much hides it. Of course, when you're up on the TTA, you'll see it clearly. But many attractions that give you height often break 'sight lines.' (I'm on a Tomorrowland ride, but I can see four different lands!!!)
Once you round Speedway and head to the RR station, the BBB is obvious. (As well as the BoH building between Dumbo and Speedway painted go-away-green... but I've never seen anyone complain about it.)
Once you pass the station and start walking along the shortcut patch between Circus and Tomorrowland, there is a wall of tall Arbor Vitae that you're right next to, which completely blocks the view of the BBB.
Plant more of that elsewhere, and almost all sightline problems (from within the park at ground level) disappear. The most recent pictures of the site show tall, full trees being planted to hide other sight lines, such as what will be from the train.
