Ok, now some of your rants are clearer.
I see no reason to spit out perfectly good wine (unless I'm tasting a lot of different wines and don't want go get squiffed). In the normal course of drinking wine with food, however, I do sniff (this brings me pleasure, as the aromas are usually worth the snort), I do sip (as opposed to gulp, but this is merely quantity control, not an affectation), and swill (that is, swish the wine around so that I can get the most taste sensation) without making a big deal of it. Yes, different areas of the mouth respond differently to food.
(as an aside, try eating with your opposite hand, and on the opposite side of your mouth - there actually is a subtle but noticable difference from what you're probably used to)
Sometimes I do "wine tasting" when I'm going from winery to winery to pick out the wines I want to spend money on and carry 3000 miles to home. I usually swallow those too (why waste it) but one can end up drinking enough to dull the senses that way, so spitting out (especially the wines that are... er... less sensational :) is not a bad idea. But this is a special case.
I suspect that most people who "taste" wine are either really "drinking with food" (or drinking without food) and calling it tasting, or are simply choosing what to buy.
Jose