Not everyone is fit for Da’wah, and not everyone who has enthusiasm is right for Da’wah

“Not everyone is fit for Da’wah, and not everyone who has enthusiasm is right for Da’wah. Enthusiasm coupled with ignorance brings harm and does not benefit.”
Shaykh Salih Al-Fawzan, Al-Ajwibat-ul-Mufeedah, p.79

Why are muslims not able to name any present day 'ulema of ahl us sunnah?
yet won't stop praising and mentioning the names of :
-celebrity speakers
-deviant callers to hellfire
-liars
-jokers
-people of worst manners/conduct
-unknown individuals
etc.