No. A lower than average ability score means you are less likely to succeed at related tasks on average. The difference from being proficient in a skill is greater than the difference between the modifier on a 10 and an 8 (and equal to the difference on a 6). The difference between higher level characters is even more extreme. Yet, one rarely (if ever) sees suggestions that 1st level characters should be role-played as incompetent, foolish, or awkward.