Some time I see people drinking red wine and not holding the glass by the stem, but by the base.?!

The truth is, everyone should hold the glass in a way that is comfortable for them. Some wine experts believe that wine should be held only by the stem or base to avoid changing the temperature of the wine. Others disagree. Some people hold the stem or the base, instead of the bowl, in order to avoid the appearance of fingerprints on the glass.

Go with what's comfortable for you. They're okay. Sure, they may be snobs, but they may not be.

Former wine salesman, cook.

White and blush wine (wines served cold) are really the only ones that should be held by the base or stem. For reds it really doesn't matter if you hold it from the base, stem or bowl.

actually that's the proper way to hold the glass