Interesting, I thought that only exit nodes carry a reputation risk. I guess there must be some really zealous scrapers who ban middle nodes based on the public list.
Entry nodes also run a big reputational risk. A number of list providers filter them. Many organisations want to prevent their users from accessing TOR to bypass filtering or exfiltrate data.
All nodes are allowable entry nodes, although the standard client uses a guard selection algorithm that ensures the entry node will always be one with a good uptime record.