Can you give some example where you noticed this, and some time frame? Because at least during the high and late middle ages and early modern period, I don't think this was the normal case, especially not in societies in which the vast majority of farmers were serfs, while artisanal (and tradesmen, granted) guilds, such as the Worshipful Companies of London of the Gaffels of Cologne, could become powerful political players in their cities.

Speaking in the American and (most of) the European traditions, I know of no time when artisans were looked down upon in any overarching way.

Is it possible that you're confusing artisans with merchants? It is true that many merchants were looked own upon by the upper echelons of European society as the merchant class rose to challenge the authority of the landed gentry.