Bed bugs are a big problem now, even in 5 star hotels. I stayed in a very nice hotel in OKC, and had bed bug bites on my arm, they moved me, and more bed bugs, they bought me a new mattress (I was staying 9 months, son was in hospital there), and finally no bugs. I decided to clean my own room after that, washed the bedding myself in guest laundry including my towels..got a discount because of the long stay and self cleaning/laundry. But just a night or so in a hotel, guess we take chances, no matter how high end the hotel is...too many international travelers, it's not just over seas problem any more, it's all over America too now.
Fabrics, with chemicals and 'bugs', and because it's flu season with everyone sneezing or touching fabrics, good reason to prewash. I know Moda, Kauffman, higher fabrics 'cure' in a hot steam rm sealing dye color and some preshrinkage this way (no prewash needed) lower end fabrics should prewash as dye isn't cured, but in transit, or in store, everyone sick, good reason to prewash anyway.