I think a judge or jury would have to weigh all sides of evidence. On one hand, I agree with you. Oil slicks or coolant leaks should be addressed.
But I would say, that level of expectation is probably reserved for a specific event. A race, I agree completely. Corners workers, safety personnel and ambulance should be present. It's a racing event and expectations are higher. However, on just a normal track day, one could speculate on the amount of attendants or attention a track should receive. Open lapping days are more relaxed and people aren't in competition. Things can happen at track days but then again, anything can happen to you when you walk out the door of your home.
In my opinion, when it comes to Open Lapping track days at PMP. You should show the utmost diligence and ride within your own limits. Open lapping isn't about racing, it's about improving as a rider and enjoying the day at the track. I think if more people could get that through their thick heads, then track days would become safer because people wouldn't be pushing their limits.
The way I look at it, when I'm doing an Open Lapping track day. I'm riding to have fun and improve as a rider, slowly and lap by lap. I'm not paid to race or win races. So I'm not going to push past my limits to ride on the ragged edge. Honestly, I wouldn't ride on the ragged edge even in club level racing. Unless I'm a professional racer where someone else is footing the bill, then I'm not risking everything for nothing. Yeah if there is a nice fat paycheck involved, then I'll go to hell and back for my team. If I'm the one who's doing all the maintenance, pays for everything, then I'm going to take it nice and easy and have fun. I'll work on being a better rider and care less about setting record laps.
When riding at the track, it's all relative what's important to you.