The funny part is that I never heard a professional tell me I should use WD40 for a specific task. It's been developed for (W)ater (D)isplacement, it's really good for that; and it's passable at other tasks too. For DIYers, it's fine.
For professional use-cases, targeted products are preferred, whether they be lubricants, penetrating oils, rust remover, etc.
For professional use-cases, targeted products are preferred, whether they be lubricants, penetrating oils, rust remover, etc.