As stated in above post, these high performance scopes are meant to be used very close to signal being measured and be configurable/stackable to get synchronization/more performance out of them. Thus the need for relative small size and semi-remote control.
Well, really, a lot of scopes are used "very close to the signal being measured", that's nothing new for ultra high bandwidth scopes like these. It's also not the reason for the small size (the LeCroy LabMaster is certainly also used "very close to the signal being measured", and it's digitizer blocks are much larger).
The reason why these Tek scopes are so small is primarily because they are designed for rack use (something you can't do with a LabMaster, which is essentially its own rack). Useage in ATEs is also the reason why Tek focused on remote control-ability.
This, of course does not change anything for bench scopes, but it adds possibility to have a proper small modular scope. Bench scopes are big box/brick shape but they could be made much slimmer if screen and control surfaces were to be detached as separate modules.
There already are lots of modular scopes out there, and have been for decades.
Basic scope could consist of only small and slim acquisition/processing unit with video out. You could then add external screen and external control module if you like. This could allow much more flexibility in tight workspaces as processing unit/display/control unit can be placed in different locations in the lab. Kitchen comes with built-in heat plate, lab could come with built-in scope 
As I said, stuff like that already exists for a very long time. The problem with modular kit is that it is very expensive compared to integrated units, and because modular scopes are predominantly used in ATEs or similar environments you usually have to do the legwork yourself in terms of software.