Haven't read a single response from someone who parks next to the only RV and why.
The only reasons I can think of why I would do it would be site location, and that has already been disqualified. Other reasons-
I'm nervous of the area, but then if that were the case, I wouldn't know my neighbors either would I?
They may be hoping you have a wifi hotspot they can piggyback on.
Your the "host".
You are a safety net who may be able to provide instructions, physical or medical assistance in case of breakdown/malfunction/emergency, etc.
I cannot count the times I have seen RVs pull into a campground and slowly cruise the sites. They eyeball the neighbors just as much as the spot they may or may not choose.
If I were boondocking and desired to be alone, the sight of an oncoming RV may cause me to chain my collie or wife's barking sheltie to the front jack, and turn the music up. If that doesn't do it, I'd then choose to stay or to go.