@Penny386 It's actually a very, very common rule on Airbnb that only registered guests are allowed on the property, we have the same rule for our humble Jersey City apartment. The rule exists to prevent parties and extra, unregistered guests being sneaked in, as many properties charge an extra guest fee over a certain number.
I have no idea what the reason the host called the police might be, but I suspect that more was going on here than what you have outlined, since the host, seemingly, generously, did not mention that she felt the need to call the police/try to shorten your stay, only that there was a lot of 'drama'. There is also the fact that the rest of the reviews on multiple properties are all very positive, this makes your stay seem like an outlier. You're probably correct that Airbnb is not the best fit for you, not everyone is a good match for the platform which in theory requires more attention to detail/behavior from guests than a hotel.