Sometimes a ground dish can go close to house if trees not in way. Other times you need to get beyond trees and it becomes a long buried run. I saw a lot of outfits put dish on pole right at the house, which made little sense to me. Most of my mounting was actually directly to house structure at a height accessible without ladder, as preferable to going to roof, but sometimes trees or other factors dictated the roof. But you have to be prepared for doing that work- mounting to varying surfaces such as siding, masonry or stucco, having notched mounting pads, using long/thin deck screws into studs rather than thick lag bolts. Much less of a sealing issue than on-roof. With a pole 1 or 2' from house, you still have some of that instability vulnerability, coax into ground for at least a short ways and usually have to prepare concrete. I suspect install outfits just used that as a basic go-to for less-skilled installers- knowledgeable judgment/experience has to go into on-house mounting. Conversely, other outfits would automatically go to the roof even when a side-structural siting was doable. Again they had probably just told installers to put on roof as a "pat answer" so that there wouldn't be need for using finer judgment.
Then yes, I would run the coax along/under siding to entry point, to avoid ground. But you're still going to have the offair issue where roof is unquestionably best, unless doing a tower or something.
