Yikes. Just saw that thread.
I think in this case I agree such sentiment is misplaced. However, I'll try giving the other case as well because it has a degree of legitimacy to it, in my experience.
There is quite a lot of judgement against Indian Sikhs by NRI communities as well. Go to social media on Indian Independence Day and you will find a lot of self-appointed parcharaks claiming how Sikhs who celebrate that independence day are disgusting, self-hating, and a shame to the community. Meanwhile, these are the people who happily pledge allegiance to the country that enslaved black people en masse and committed genocide against Native Americans, or the country that committed Komagata Maru, or that violently imperialized South Asia. Don't get me wrong--I'm a proud American too, and I personally believe that this country is amazing and much more favorable to India. I don't care about Indian pride. I'm not Indian, I honestly don't give a fuck about it with regards to my identity and Indian nationalists end up bugging me more than American ones. But keep this in perspective before you lambast those who live in India.
Another thing is that many NRI's seem woefully ignorant of the problems going on in India related to Sikhs. Case in point, social media parcharaks going all "This is why India is a failed country!!!" when the news about Bapu Surat Singh came out. No, actually the Indian Supreme Court upheld the rights for such cases; it is a sad example of the petty politics of the Badal regime that still holds power because many people can't recognize that our problems have gone beyond the central government. Everything is a conspiracy from the RSS/central government to undermine Sikhi (this is one thing that bothers me about Jagraj Singh as well). Therefore, Indian Sikhs are framed as "feeble," as "lacking a backbone," as "blinded by the propaganda," for not advocating for Khalistan and freeing themselves from the shackles. IMO, people aren't advocating for a Khalistan generally speaking because the problems that led to the Khalistan movement are not what's affecting Sikhs anymore. It disturbs me when NRI's think they have the right to declare Punjab an autonomous theological state. How is that any better than when a group of Indian Sikhs burnt American flags in protest of the Oak Creek shooting?
ALL THAT SAID...generally, I think many Indians are very ignorant of the own people within their country and of those outside.
"Only these hateful NRI's support Bhindranwale and the militants, all those within here are loyal to our country." Um....if you want a Bhindranwale poster or memorabilia of any militants, you have to go to India to buy them because they're commonplace in markets. Indian social media is rife with pictures of him on Bluestar anniversary (even one of my uncles who is a smalltime Congress politician posted it). The Badal's and even Capt Amarinder Singh still have to spend a lot of election energy appealing to politics from 1984. Hell, a lot of the media around 1984 is super popular in India. It's not connected to Khalistani politics, that's for sure...but even among most NRI's, Khalistan is more symbolic than an actual goal.
"These NRI's are happy scrubbing toilets and facing racism for a quick buck" I would much rather work labor and earn money from my own hand than the reality of many Sikhs within India who sit and drink cha all day while the Bhaiyyas out in the field do their work for them.
"NRI's are intolerant against Hindus!" Most of us live in multicultural societies with people from a variant of religions. Just because we do not have a special affinity towards Hinduism does not mean we are "hateful" toward Hindus.
As for the context of the original article, many Indian Sikhs themselves including the jathedar of Akal Takht started freaking out about this and said Sikhs need to have more babies.
If there's a summary to what I have to say: treat people as individuals and don't box them into categories of NRI/Indian straight off the bat. As a whole, we actually share a lot more in common than you may think, negative and positive. And if there's difference, try to resolve it through actual discussion and education over petty insults.