I used to travel a lot for work and I would submit my expenses to the Accounting department. I got a “tsk tsk” email once saying $5 was too much to spend on tipping housekeeping and for that tier of hotel,(I think it was a Hampton Inn) I should tip $2–3. From then on I just tipped out of my own pocket but in retrospect I should have made a fuss. This is a company that spends tons of money on fancy receptions etc. but can’t compensate housekeepers?