I know that there is often a lively debate about tipping hotel housekeeping staff. I like to tip the housekeepers who work for very little money and overall do a very good job. My question is why don't the hotels do something to make it easier to do? I don't like to carry cash but that is the only way to tip them. Why isn't there an envelope where you can either leave cash or sign to put a tip on your hotel room bill? I think it would greatly increase tips for housekeepers and make their staff much happier.

There are hotels that provide an envelop for tips.
You can't put in into your hotel bill because the whole point for tips is to tip the housekeeper that cleans your room. Also I don't think housekeepers necessarily want IRS to know how much tips they got

Anybody have any insight into tipping at restaurants in Bahrain?

The restaurant bills have a 12% "Service charge" included but everyone says that it goes to the owner, not the servers.

When a London hotel says "breakfast" I expect it to include eggs, bacon and other items. When a Paris hotel says the same thing, I expect a croissant. I don't whine about the difference or assert that one is better than the other.

Same thing for tips. In the USA, tips are part of an individual's income and they are expected as part of the culture. The prospect of tips can be used to reduce the minimum wage and may also be used to calculate income for income tax purposes. That is whether the tip is paid or not.

This is not the case in the UK. Arguing about which system is better is like arguing about whether having an elected or inherited Head of State is better.

If you travel in the USA and don't tip the waiter, just understand that you are actually chiseling them. If you travel in the UK and do tip, just understand that it's some extra for something above and beyond.

That is not necessarily true. Several states (such as California, for one) prohibit tips from counting towards the minimum wage.

That is not true either. Servers can keep track of their tips and pay taxes on the actual amount rather than the default allocation if they choose to do so.

While pretty much all tipped employees prefer cash for the reason you stated, I think they would all prefer credit card tip that is reported to the IRS vs. no tip at all.