Don't think they have a problem to hire someone with 12 years experience for the price of 10 years

Speed limit signs with ranges would make sense if given some additional clarification by the issuing authority. For example:

• The upper bound is the limit in perfect conditions; the lower bound is the limit when the weather is bad in any way
• The upper bound is the limit when there’s no traffic. The lower bound is the limit when there’s substantial traffic.
• The upper bound is the limit normally. The lower bound is the limit during school hours.

Even without a clarification drivers could probably assume it’s some combination of the above.

(A job description could have the same clarification but probably doesn’t, as “minimum” is just an error on the part of the person writing it. But they could say “5-10 years minimum experience, depending on level and nature of education,” and then a reader could infer that a person with a relevant Master’s degree might need 5 years of experience; a relevant Bachelor’s degree - 6 years minimum; a major in something else - 8 years minimum; only a high school diploma - 10 years minimum.)