Given that Dayananda Saraswati objected to much of popular Hinduism, and also given that his arguments against Christianity were flawed, one must ask why he had so much success.
The answers seem to be multiple.
(1) He organized his version of Vedic Hinduism along – ironically – the lines found in the Semitic religions. For example, in his version of Hinduism was characterized by
(1.1) one single and singular holy book, the Vedas,
(1.2) a creed (the 10 Principles of the Arya Samaj), a fellowship – the Arya Samaj (who btw, initially identified themselves as Aryas, not as Hindus)
(1.3) a slogan – “back to the Vedas!” (During the reformation, the refrain was “Sola Scriptura!”)
(1.4) a missionary organization – the Paropakarini Sabha
(2) He switched from giving talks in Sanskrit to giving talks in Hindi, the lingua franca of the masses. ==> Contextualization
(3) He also switched his dress style from using just a loin cloth to … I do not know what it is called… but became dressier. ==> Contextualization
(4) Again ironically, he adopted Western styles of disseminating his message – passing out tracts, articles, etc.
One other thing – Why did Dayananda Saraswati have so much success in in Punjab and not in his native land. Apparently it is because of
(1) the pre-existing work of the Brahmo Samaj there and the demographic landscape of the area.
(2) The population of Punjab around 1875, when he founded the Arya Samaj there was 51% Muslim, and 7.5% Sikh. (See Hindu Nationalism: A Reader by Christophe Jaffrelot). In addition, you had the Brahmo Samaj there also. The Brahmo Samaj did not just sit tight and do nothing. They spread their message by passing out tracts, giving public talks in the streets and so on. (Double Check this).
So what I am saying is this… In the Punjab, Saraswati entered an environment that was by in large monotheistic and the Hindus there also by in large had been exposed to Monotheism, and I am sure – had their polytheism challenged.
So now enter Dayananda Saraswati … who comes offering a brand of Hinduism that is overtly monotheistic . . .