I've spent enough time [Edit: on HN] to remember App.net¹ which was launched with similar fanfare but was shut down after few painful years of trying to find a PMF. The lesson I learned from that saga was HN might not be the best place to validate your product. We're too smart to diss even good ideas like DropBox.
Go and talk to your potential customers and I hope the App.net story gives you some inspiration.
I also want to add: HN is an especially bad place to validate this type of product because HN has the exact same interface as reddit. This post is popular because of its novelty, there is an incentive to upvote this post and say whatever OP wants to hear in order to get him to keep working on this project. Because "having alternatives never hurts". But it hurts the person developing the alternative. He already lost 4 years of his life to this. Hopefully he wises up and pivots before he wastes another 4 years.
Go and talk to your potential customers and I hope the App.net story gives you some inspiration.
1: https://news.ycombinator.com/item?id=4372985
2: https://news.ycombinator.com/item?id=13387723