Derech: Learning Torah is not our only purpose in life. We also need to do mitzvos, including acts of kindness. We are very limited in the acts of kindness we can do for others if we have no “secular” skills or knowledge.
Being a doctor, a plumber, an engineer, whatever, whether it’s part time or full time, enables you to help other people much more effectively, both through giving tzedakah and through giving practical assistance to others (something the Shulchan Aruch says we should always be doing).
I would rather have someone whose mind is 50% Torah and 50% Engineering, if that person’s engineering skills save one person’s life, or save one person from great suffering.