The words you use certainly are important.

Why aren't you doing XYZ??

Why ask this when it's already obvious the person doesn't know what XYZ does or how to use it? It is pointless, accusational, and invites the other person to either admit ignorance or tell you to get on your bike. unsurprisingly, some are going to choose the latter. Either way, you aren't making any friends that way.

There's no need to challenge other users in this manner, it's counter-productive. You can make a general statement about what works/what doesn't - and don't expect an immediate reply, you also need to give the player time for it to sink in, maybe change their hotbar, etc. Just firing off challenges and expecting the other player to immediately fall into line and thank you profusely is a problem of your own expectations. What you will never know, is if that player took your comments on board and used them in their next dungeon.