I gather that 1911's from specialty makes (Kimber, Wilson, Night Hawk) may need tuning and/or gunsmithing out of the box. This just seems to be something that's accepted by the buying public and is more likely with mods that deviate from the standard 1911 design.
I think Kel-Tec's reputation has to do with the fact that their niche is pocket guns, which are notoriously unreliable out-of-the-box without tuning. Other makers of pocket guns - Kahr, Rohrbaugh, North American Arms - all have similar reputations (as do the major manufacturers that do pocket guns). Seems to be due to the nature of pocket guns and is made worse by the low price point that Kel-Tec operates at.