Just because we have become indoctrinated that Torah is the only umnus (for which one must be rational and question whether this is for every single person), that does not make the billboard less than 100% OK. The sponsors are aware that not every bochur is destined to be klai kodesh, and cookie cutting them to remain in full time learning is likely NOT ratzon Hashem. The message is to remember the holy words of Chazal, then interpret them according to what HKB”H really demands of us.
Maybe not every single bochur should take secular studies. But that none should be prepared for work is equally if not more ridiculous.