Mat 60, not offended that you prefer working with kiln dried lumber, and I think you give an interesting perspective. But perhaps your recent gift wood and other air dried lumber you've worked with was not handled or processed well.
In regards to air dried being dirtier, it's not the process but rather the processing and those doing the processing. I also think most kiln dried stuff is done by those who do this stuff for a living and have the equipment, facilities and know how. More experience and knowledge means less dirt.
In regards to working with air dried, I think it is definitely better for bending, turning and retains more vibrant color. Some forms of chair making requires it also.
Kiln dried lumber may have less warping, again because it is likely processed by more experienced individuals, but I do think it can have more internal stresses built up within the wood.
And in reference to Sawyer Rob's comment above, careful and correctly monitored air dried wood isn't likely to be much different than kiln dried, except for moisture content.