Apparently, a lot of wires can be stuffed into an electrical junction box... However, this installation doesn't meet the National Electrical Code requirements.
You could say, the more the merrier... But not in this situation.
Too many wires stuffed into a box can cause dangerous overheating, short-circuiting and fire. The NEC specifies minimum electrical junction box sizes to reduce this risk.
What I'm talking about is 'box fill'.
Electrical junction boxes all have a certain volume that the wires can occupy. This junction box appears to be a 30 cubic inch volume size.
My recommendation was to recommend further review by a licensed electrician... Funny how the home inspection report plays out.