NP, on Kiddushin – Gemorah gives us ideas here, not necessarily final answers that may depend on social conditions. You can see it in the gemora itself. For example, they learned and then married in Israel and opposite in Bavel – because they did not dorm in Israel.
So, when there is an opportunity to have reliable businesses without umanut – gezunte heig. This was during years of R Moshe, where one could have run a local store in Brooklyn and have an honest living. If you see now yeshiva graduates trying to outsell each other on Amazon selling same smartphones, then it is an issue if metziyt: is this working or not?
Same goes for the siyum of Kiddushin: R Nehorai dramatic statement is there for the siyum, but it follows multiple Rabbis going into details of what is a good profession. Some notice that he says “to my son”. As most people at that time went into professions, obviously, the other opinions were important.
And, again – it is matter of facts: if R Nehorai’s son would have parnosa or middos problems, he would surely change his approach. As R Aha Yaakov does in the original sugya: where he confirms that his son is learning worse than him, so he lives the kid to work in the field and goes to learn himself.