Sorry, but Christian de Portzamparc was born in 1944. Rem Koolhaas was also born in 1944. He was 56 last year when he received the Pritzker. But there should be no excuses made for giving the prize to older architects. The drive doesn't disappear after fifty.
Architects keep on working until they die.
Look at Aalto, Corb, etc. In some cases it only starts operating after 50. Look at Alberti. You should say that, instead of trying to justify whatever you are trying to justify with your erroneous information.