Summary: A black belt is supposed to denote that the one wearing it is an expert. One does not become an expert at something over-night. It takes years of practice, study, and effort.
Agree and disagree; first the disagree:
Most styles that I am familiar with do not consider a blackbelt to be expert, merely proficient; proficient in technique and a proficient fighter. One who has "learned how to learn." Using kendo as an example, a blackbelt is considered a beginner. A second degree is someone who is developing a fuller understanding of kendo. Master, or expert is generally not until fourth or fifth dan.
While proficiency does not come over night either, depending upon the number and type of techniques a form has becoming proficient in the basics can take a different amount of time from school to school.
Having said that, I do believe that a blackbelt represents a
proficient fighter in that style, which is different from being proficient in techniques and forms. One can be a very proficient kicker or puncher, kicking and punching with the proficiency to break boards, bricks, or whatever, and with perfect form, but still not be able to fight. If you can't fight proficiently, but hold a black belt, then there is no point to learning the forms and techniques, particularly if you quit after you get your black belt, which most students do.
Now, where I agree: to be an expert in anything takes a very lengthy time. If a style holds that blackbelt is an expert, but hands them out in two years, then I would have very serious reservations about either the curriculum, the quality of the instructor, or more than likely, both.
Getting back to my kendo example with regards to where one is considered 'expert' in the style, time in kyu ranks is
at least two years, another year to second degree, two years from second to third, three from third to fourth, and four from fourth to fifth. That is eight to twelve years to fourth/fifth dan, plus there are minimum age requirements for higher dan ranks.
And that is for the use of
one weapon! So, regarding Crippler's last sentence,
One does not become an expert at something over-night. It takes years of practice, study, and effort.
I agree 200%.
Daniel