Balabus,
“why is leaving yeshivah frowned upon.”
It is up to each person to assess how he can best serve Hashem and work towards that goal. This does include financial considerations, a desire to utilize talents to serve or create things for people, etc. My guess on the frowning is that…
“the yeshivah system is just not for him”
is a cop-out type of reason showing that serving Hashem is likely not at the center of the man’s motivation.
“i think moshiach will come when the world can finally grow up and not judge/look down at other people because they left yeshiva.”
So this puts the OP squarely into troll territory, but I answered seriously because the subsequent discussion was serious.