If they are 'fat' dishes, the amount of unwanted noise from satellites next to the one of interest is less
With 28 East there is little chance of picking up stuff either side, but on satellites near to say 16 East, a dish thats wider than tall removes the adjacent signals from 13 and 19 East better than a tall one.
Additionally the impact of the dish to objecting neighbours is reduced.
err nahhhhhhhh Pipe type maybe ........... But a bloody ugly "Zit" slap bang in the middle of a terraced house, looks freakin nasty what ever orientation its in...... Don't Skys installation chaps go to "Good Taste School" ?
I would say that the lower impact was a pretty major benefit. When Sky decided to go to digital, the major objection they had heard from analogue customers (aside from price), was the obtrusive nature of the dish, so by making it considerably smaller, that was one objection to having satellite, partially dealt with. The zone one minidish also appears to perform pretty closely to a standard 60cm dish.
Squarials were just too expensive, and failed regularly.
Active electronics in an array is asking too much trouble when mixed with
1) An aerial rigger
1a) A Sky installer
2) A domestic installation
3 The power supply of the consumer electronics connected to it