Why do soccer clubs not retire jersey numbers?

They do..But only a few.. Although it is common in American Sports culture that teams retire the jersey no. in honour of their famous players for their loyal service, it is new to the world of football. read more

Generally clubs instead of retiring a Number, tend to hand it down to the one they feel is worthy of living upto the reputation of the jersey. Sometimes a particular No. becomes associated with legends and the club may feel that they should carry on that legacy. read more

Some clubs dedicate a number to their fans, and do not issue it to any player. The most common number for this practice is 12, from descriptions of the fans as "the twelfth man". In Japanese footballing tradition, almost all the professional teams retired the number 12 for their supporters. read more

" Soccer shirt number, position, meaning, famous" This link gives the newer and more robust meaning to each number and where traditionally the numbers would play. extract from it as to numbers that have been retired (ie never to be used again) "Retired jersey numbers You may have come across the term “retired jersey number”. read more