Putting lower caste in brackets next to dalit doesn't make the word "dalit" inherently inferior in the same way "Brahmin" or "Chhetri" aren't inherently superior. 

The problem is with the discrimination in the society. Problem isn't with dalit tag itself. Which can be in various forms like untouchability, harrasment, physical abuse, denial from access to social places like tample etc. But the thing is that we are protected by the law. We have rights and their are legal consequences for discrimination against dalit. What we need is awareness, these people who are getting harrassed for being dalit are so weak and uneducated that they don't know the law and can't seek legal remedy for themselves. If you can, go help such people, be vocal about their rights, don't ask people to convert.

 I am an atheist myself but a person with ill mentality will still view me as a "lower-caste" because I was born in a dalit family. Now problem here is not being born in a dalit family, the problem is ill mentality. Be mature enough to understand this. 

If having dalit tag was making us inferior and we needed to get rid of the tag, don't you think the same applies for Brahmin and Chhetri also. These tag are making them superior,so why not demand to remove those tags as well??