In RM2, I have made a Blacksmith from the Profession profession and a farmer from the No-Profession profession.
In that other roleplaying game that uses a single die with twice the numbers on it, I've made a Dwarf Wizard (he had 4HP) and I've made an investment banker type. He was sent out by the bankers guild to find new markets in which to bring the banking guild's "very reasonable interest rates for loans and investments" to other regions. As a result, he needed to travel with adventurers who could help protect him. His specialty was gems so I gave him skill in 1H Hammer.
The Dwarf Wizard was tired of being pigeonholed and expected to do mining when all he really wanted to be was a lumberja.... errr. wizard.
For the RM2 PCs, the Blacksmith was part of the entourage that travels with an adventuring party. He was one of those behind-the-scenes characters that helps keep the party train going but never gets any credit. The party was having a lot of interaction with him as an NPC so I turned him into a PC I could actually play and he worked out great.
The Non-profession Farmer was seeking revenge because his wife and family were killed and he was suddenly thrust into the world of adventuring. As luck would have it, he was able to find a Bounty Hunter and an Assassin for hire at the local tavern! What great luck for him (and the other two players sitting at the table with us that session)!
The difference between these makes the comparison not work well, imo. Sure, when talking about modern people most don't have "adventuring/combat" skills or abilities. But, the average farmer in the average fantasy setting will. So, they will not be as "useless" as the kids with no magical abilities of yet.
The non-adventurer doesn't may not have what one would consider combat skills, but every day life in their chosen profession would be suitable for combat. The Blacksmith I made had lots of ranks in 1H Hammer skill, high Con, and lots of Body Dev just by nature of his work. He also had Hostile Environment - Heat, Smithing, Forging, Metal/Weapon/Armour Eval, Trading skills, etc. All easily translatable into a life of adventure and a good jumping off point.
Also, the adventurers don't have to be kids with no magic skills. My party had a level 1 spell user with two spell lists.... neither list had a level 1 spell to cast! LOL He made do with other skills and his bow until he hit level 2.