This is likely a debate for another time. While i don't disagree with anything you have said, I also look at their life in Dubai vs. their home country, and I think they are in a much better place with much better opportunity. So, while to our standards they have it rough, compared to staying in their home country they might be quite pleased with being employed in Dubai.

Having said that, I do often tip the CD, either 10 or 20 AED, and when I have't had AED I have given them whatever currency I have. I don't tip them because of their hard life, nor because I don't think they get paid enough, I tip as a token of appreciation if they give good service. If the CD just drops me off and doesn't get out of the car, I don't tip. If they get out, attempt to open my door (I usually just get out of my own), open the trunk and help get bags out, then I do tip. And, that is just me and how I like to do it.

There are 3 zones in this world. Where tipping is expected, where it is a no-no, and where it is graciously accepted but not expected. Dubai is definitely in the 3rd. It is fine not to tip and it is fine to tip, it is up to the customer.