Having read quite a few of these threads, I tend to think that a lot of posters book self-catering with the expectation of 5* hotel service.
Yes, you might have paid £3000 for a week in a Welsh cottage in August, but I can guarantee that the owner is not getting £3000 for 52 weeks of the year. When you start taking into account cleaning costs, costs of maintaining the property itself, insurance, constantly replacing broken or stolen items, the hospitality items that everyone on here seems to demand (organic butter, milk, cakes, bread, biscuits, honey, juice, tea, coffee, sugar, other condiments etc plus a never ending supply of toilet paper and cleaning products), expensive kitchenware, top end white goods and god knows what else, it quickly becomes fairly uneconomical.
Obviously, just as this thread demonstrates that there are a significant number of guests who take the piss, there are also owners who take the piss, but if you want 5* service and don’t expect to so much as buy a single toilet roll, you’d probably be better off booking a hotel.
Re. breakages, yes, we expect a certain level of them, but in my experience, a lot of damage goes well beyond accidental. It can only really be down to people not giving a shit because it’s not their house and a sense of entitlement that they’ve paid to be there, so they can spill milk all over the sofa and not bother to clean it, or break the shower, or yank a blind off a wall or pinch a couple of those pretty bowls.