Very few among general public question a printed work believing it as some gospel truth. The way printing (including web printing and modern electronic media) transformed religions had never happened in olden times. This continues to transform even today more vigorously with tools like whatsApp, wikipedia and facebook becoming vehicles of propagation of new ideas and interpretations. This is true for most faiths which all transformed to newer versions based on newer interpretations by people having significant following of their own. With advantage of mass distributable media, they made their versions significantly popular representative of some supposedly ancient and sacred books.
Biggest advantage for Ramchritramanas or for various versions of other religious texts which we find popular in our times, has been that these received advantage of bulk reproduction and distribution leading to achieve immense popularity as we observe today. The ancient books never received advantage of mechanical printing and particularly offset printing at the time these were conceived originally, and being loosely conserved and propagated through chiefly oral means got subjected to additions and revisions by many sects and commoners alike.
Printing technology which emerged some 300 years back in India made these texts like Ramcharitamanas easily distributable universally. Whole cult of reading printed religious books together in groups also emerged because of easy availability of books everywhere, organisations and people distributing them. Plays started being enacted in streets and in village fairs based on printed books and booklets available widely making these story versions not just popular but giving them sort of status of guiding reference defining a religion.