"Best known for" is an opinion.  There is no possible way to objectively establish what he or anyone else is best known for.  The statement does not clarify anything.  It adds no information to the article and it's very easy to avoid.  One can simply state what Adams achieved, without applying any judgement as to which of his achievements are the most widely known.
Neither the length of time a phrase has been in an article, nor the number of other wikipedia articles which contain a similar phrase, are very good arguments about the value or otherwise of the phrase. 190.46.98.195