We have multiple versions of Vishnu Sahasranama in our scriptures like Mahabharata, Padma Purana, Skanda Purana, etc. But the Mahabharata version is mostly used by us. So apart from the fact that Mahabharata is more popular than the other scriptures, is there any specific reason why that version of Sahasranama is mostly used and recommended by saints?
I wasn't aware that Vishnu Sahasranama has many versions until I read this question. So, I am unable to verify and compare them to answer. However, I remember a view point of one of the upanyasakar (person who delivers religious discourses) that this sahasranama is great because:
- It is asked by Dharmaputra who was a great person following dharma to the core.
- It was asked to a great purusha - Beeshma
- And more importantly, it was witnessed by the Lord Krishna himself when Dharmaputra asked those 6 questions and Beeshma answered explicitly mentioning the Lord Krishna while all the three connected were physically present together.
The upanyasakar said that Krishna endorsed the answers of Bheesma and hence this is the superior of all.
Puranas are a gain lesser importance with respect to Smirti granthas. Mahabharata which of course is a Smriti grantha, because Badarayana often quotes Vyasas BhagavadGita as smriti pramana in his SharirakaSutras (Vedanta Sutras) [1-2-25,1-3-23 etc]. But moreover it is considered as Panchama Veda (abridged Veda for all). Hence Smriti Mantras are more powerfull and nearer to Veda than Purana Mantras. So Indian saints from all castes have always preferred Vishnu Sahasranama of Mahabharata.
It is hard to be certain as to WHY this version of Sri Vishnu Sahasranama is the most popular, and it is equally hard for me to answer this without factoring in my understanding / opinion, or with a reference. The reason is I am not aware of a place where the reason for the popularity is clearly explained. Any such note, if found on the internet, has higher chances of being an individual's opinion than not - unless of course, such an explanation is part of one of the Puranas (which I don't believe to be the case based on the Puranas I have seen so far).
So my answer is, this version of Sri Vishnu Sahasranama became popular, probably because His Holiness Sri Adi Sankaracharya commented on it. Following his commentary, other acharyas also commented subsequently though much later. What happens is, when such commentaries are written by acharyas, the work gains credibility and popularity, their disciples propagate it further, and it continues to be included in daily worship and other observances.
Again this is an opinion, but I have seen comments by modern scholars crediting Sri Sankara for bringing some of these texts and slokhas to prominence by being one of the early commentators, if not the first commentator. So this is following the same line of thought.
But based on what I read, my working hypothesis is Sri Sankara's commentary was probably instrumental in the popularity.
Similar reasoning can also be observed about Sri Lalitha Sahasranama, though His Holiness Sri Sankara did not comment on it. But other scholars did, and that is the most popular for Devi upasakas over others such as Sri Durga Sahasranama, Sri Parvati Sahasranama, Sri Bhavani Sahasranama, and Sri Gayatri Sahasranama etc.