Because it doesn't take water to kill a MAF. Vibrations alone can sever the filament inside it. But anyways, sounds like you have your bases covered already and seeing as you don't off road, you needn't worry about vibrations.
And nissandoms I didn't say "cruddily", I said "crudely". There's a difference b/w the two. When you take shortcuts like this you run that risk. Like I said, it's just my .02.
Increased Airflow alone will not kill it. It's the type of air that makes the difference. Hell, you can drive with no filter alone and it would be fine, until the dirt and grime/dust coated the sensor and it stalled out on you. An open filter like that, even in dusty conditions runs that risk as well.