I totally disagree. In "regular" D&D, the Commoner class takes the place of the Zero-Level NPCs from eariler editions of the game. Farmers, beggars, shepherds, alekeeps, merchants, wine growers, shop keepers--these are all perfect Commoner class NPCs.
And, I like how the Commoner class allows Commoners to advance, too, up to level 10.
I fully agree, Bob.
The commoner does have a place - he's basically someone who lacks most everything else. ie: a non-noble, non-warrior, non-magical, non-skill having mook in the society he's attached to. Basically, and no offense to anyone who actually knows or is in a similar position, but they're likely a person with 2 or so skill ranks in whatever their career is. Put another way, he's a fine farmhand, but probably not the farm owner; a full-time smith's assistant, but never the smith himself; a fairly adequate lay preacher, who lacks the faith, skill and magic of the adept. Likewise, he's no warrior, and can slap on even the most threadbare and moth-eaten leather armour, and wield a wagon-spoke (club) in desperate times, but he's going to hide way behind the actual warriors of the tribe, village, or community; those warriors, in turn, are hiding behind the elites, like men and women who actually have levels in fighter or barbarian, actual levels man! My point is that the commoner can be a stand-in, but can be outclassed (rightly so) by basically anyone else in the community. Even an 8th level commoner, who can probably outshine the 4th level experts in some limited areas, are going to get beaten by any class of the same level. Another example? A 6th level commoner on the fringes might swagger around his fellows, having used his feats to rack up proficiency with a longsword and wear armour, but when the regent sends in a properly-made 6th level warrior to keep the peace, the 8th level guy, while potentially useful, knows his place.
Now, whether this happened because of lack of skill, chance, fortune, funds or opportunity, that's up to you. Nonetheless, there's definitely people who have one or two ranks in something - good enough to "get by," and even live a fairly comfortable life (insofar as commoners go) - but not enough to really master it, live the good life, affect real change within their larger community, and carve out a respectable niche (and possible lasting legacy) within their society.