Aren't you forgetting that you get to add your ability score to the test now?
This rule was created with the assumption PC heroes will quickly rise to having 5, 6, 7 or even higher scores in their best abilities.
The rule is intended for those groups who feel it isn't appropriate for a high-level hero to be stopped cold by something as insignificant as a lack of knowledge or experience. It's meant for those who like their game heroic enough that merely being a high-level hero should give you a chance at doing everything
a commoner can do. Including stuff only trained craftsmen and grizzled old academics can even attempt.
Do note this rule still doesn't turn the game into D&D - getting to roll only two dice will always remain a hefty set-back. But it at least gives the PC a long-shot of a chance; instead of flatly saying "no".
Some groups might prefer not being told "it's impossible" and this rule is for them