I don't find Sriram's use of English insulting. I am always impressed how well many people from other countries express themselves in English.
I don't think that Sriram intends to be insulting, but he is using language that panders to lazy negative stereotyping of people.
So in his case he is pandering to a lazy stereotype that in order to exhibit positive attributes and be virtuous you need to be spiritual and/or believe in god. Even when someone is seeming to rebut that stereotype they simply exhibit that it sits there as a starting point to their thinking. So lets look at some other examples.
If someone says:
'Black people can be hardworking too' - I think it is pretty clear that this is based on, and continuing to promulgate a lazy stereotype that black people are lazy. Even if the statement seems to rebut the claim - the claim is a necessary element of the dialogue even if unsaid.
or
Women can be rational too' - I think it is pretty clear that this is based on, and continuing to promulgate a lazy stereotype that women aren't rational. Even if the statement seems to rebut the claim - the claim is a necessary element of the dialogue even if unsaid.
or
Gay people can be monogamous too' - I think it is pretty clear that this is based on, and continuing to promulgate a lazy stereotype that gay people are promiscuous. Even if the statement seems to rebut the claim - the claim is a necessary element of the dialogue even if unsaid.
If your mindset is such that you do not accept the lazy starting point stereotype then the need to rebut becomes completely non-sensical.
This type of lazy prejudiced language occurs all the time and forms part of classic racist, sexist, homophobic etc tropes that help to perpetuate prejudice against certain groups of people. And the same is true for atheists, often associated with a lazy stereotype that you need to be religious to be moral or ethical.