I don't now how you can not tip at all...
Some folks know why they should provide the suggested tip and just don't. I won't "namecall" on here but you can insert your own name for this type of person.
However, I believe that many folks just do not understand that the tips make up the vast majority of the income for the CMs in tipped positions. I know that I didn't when I was planning our first cruise. I thought the suggested tips were outlandishly high. It was the DIS that educated me on this subject and we ended up tipping at the suggested level and above.
Disney makes it clear to cruisers what the suggested tipping level is. However, they don't come right out and say "We pay almost nothing so your tips are most of their income." I think that is what is needed to for everyone to understand the tipping suggestions.
Peg
But agreed that is the situation. 
