It's got nothing to do with tradition, personally.
A lot of the Cybertron stuff bears very little similarity to the original designs. Chicken-feet instead of blocks, for example. Don't hear me griping about them, though. I LIKE the Cybertron line.
The problem here is that I just don't like skeletal robots.
The toys are a lot less skeletal, and they actually appeal to me.
I think the entire tradition argument is a silly red herring anyways.
You're covering fans of realistic vehicles with chunky robots, robot animals with chunky... umm... robots, futuristic vehicles with chunky robots, futuristic vehicles with sleek robots, and whatever other inane variant I missed, all with the same "tradition" label.
And completely ignoring the new cartoon lines, Beast Wars, and arguably even parts of the Alternators/Binaltech line.
There's a fairly wide range of fans that deem the movie designs crap, and they aren't ALL just obsessed with bright primary colors and robot bricks. It's ever so slightly possible that the movie designs are just ugly.