There are 2 issues with this thread;
Firstly the Ops communication has been very poor - so first of all, complaints about terrible behaviour, but no detail and just 3 pictures only showing a broken bed which would have been flimsy to start with....nothing else to warrant the complaints. Later, a much more detailed list of damage and info about the flimsy bed costing £700 when lots of people have bought a similar bed for less than £300. I'm not sure it all quite stacks up.
That aside, I think the Op sounds a rather inexperienced and unaware landlady. Firstly, whilst you should be able to expect and hope holiday makers will treat a place well, you also always have to be prepared for the fact that some won't and you do have to accept that as a risk and the costs associated with clean-up, as part of your overall running costs. Yes, in an ideal world everyone would be a perfect tenant, but people are careless (wine spilt on pale carpets, burns on tables and work tops, allowing baths to flood) and some are destructive (bouncing on beds, leaving indoor furniture outside in the rain) A professional landlord sets damage deposits appropriately, has adequate insurance and factors in significant amounts for cleaning and replacement into their budget for the costs of running and maintaining a holiday let....and when damage occurs, they feel annoyed but try to emotionally detach from it and know that this is the one in twenty experience whichbtheyvare bound to experience.
The other things a professional letter does is to equip the property for tenants. This means sensible and sturdy furniture which it would be difficult to break, easily replaceable kitchens, tiles etc, no pale carpets or white upholstery. And they expect to regularly replace things....it just goes with the territory.
So, I agree that people can be disgusting in their behaviour. Some people are awful. However, I also thinknthatbifnyou get into letting, you have to expect an element of it, minimise the risks by what you provide in the place and how you set up insurance and damage deposits, and just accept that sometimes you will have a really shitty tenant and not allow it to really really upset you. If you can't do this, then holiday letting just probably isn't for you.