Well said. It is possible for a person to

spend a few months or even weeks to learn a certain IT skill from scratch and possibly find a job with it. However in order to get to next level and thorough understanding of a bigger picture, it takes more time and effort.

By the way, those kind of database or application performance tuning work cannot be picked up "quickly". It's not trivial at all and requires accumulated years of practical experience.

I am not trying to discourage people switch to IT. Actually it could be a good try for many people, but just keep in mind that it's relatively easier to get started but may not be that easy to exceed for most people.