I always like to say, the ‘M’ in ‘Thailand’ stands for maintenance. So things like stains or some older caulking aren’t going to be looked after in a timely manner except in the most upscale places. One factor I consider when choosing a hotel in Thailand is how old it is. The newer the place, the more things work as they should, the towels aren’t starting to have threads coming off, etc. Sometimes, I don’t have options and have to put up with things such as stains, towels that should have been replaced already, etc. International chains can, but not always, be somewhat better wrt to maintenance. I’ve been to many hotels in Thailand with a lovely lobby only get to off the elevator in a corridor of stained carpeting.