Sorry I can't agree with your thoughts @Evrim4
Check in for hotels and many self catering places is often 3 p.m. so a 4 p.m. check in is pretty standard.
Guests don't see it as unfriendly or unreasonable. Reasonable guests understand that when you have a same day turnaround where guests aren't leaving till 11.00 a.m. or later it's perfectly reasonable allowing for cleaning and preparation of the listing.
Not all guests are tourists by any means, but there are lots of left luggage places a guest can use if they choose to arrive at a destination before their accommodation is available.
Doesn't sound like you have a great host, but if it's only half an hour just go for a coffee.
You are right if you want hotel style facilities then it sounds like staying at a hotel would work better for you.