All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
Islam is based on knowledge and disseminating knowledge to people is an inevitable obligation. Such an obligation is fulfilled according to everyone's capacity, and everyone is obliged to transmit only the knowledge he has.
In a Hadeeth on the authority of Ibn Mas‘ood the Prophet supplicated for the person who heard a Hadeeth from him and passed it to others as he heard, he that Allaah will shower him with delight and splendor and beauty on his face, and endow him with blessings in this world and the Hereafter. [At-Tirmithi]
Thus, those people you mentioned are trying their best to remind people of the Sayings of Allaah and the narrations of the Prophet by reading the book of Riyaadh As-Saaliheen in the mosque following the Asr prayer. They will be rewarded – Allaah Willing - particularly since they did not claim to be scholars, or claim knowledge of what they do not know. Moreover, they did not resort to this activity except when scholars and students of knowledge refrained from doing it and no longer conveyed knowledge to people.
We would like to take this opportunity to advise these brothers to acquire Islamic knowledge, so that their role is fully played and their reward will be greater. On the other hand, we call upon the students of knowledge to concern themselves with the conveyance of knowledge and educating the Muslims, because it is a great responsibility and a grave matter.
Allaah Knows best.