Really good ideas can be started at any time, and don't suffer from competitive pressure. The way i see it, there are two categories of products: gold rushes and fishing expeditions. The social space is a classic gold rush scenario. The winners in that space won almost by accident, and someone else could have easily taken their place. Google on the other hand started as a fishing expedition. If they hadn't built it back when they did, we might have used altavisa for another 5 years and been none the wiser.
I agree that Svbtle and Medium have a similar look and overall design sensibility. But in the interest of giving credit where it is due...
Svbtle's announcement is dated March 22, 2012
http://dcurt.is/codename-svbtle
https://news.ycombinator.com/item?id=3742314
https://medium.com/about/9e53ca408c48
https://news.ycombinator.com/item?id=4383283
So, I think Dustin deserves some credit for originality on this one.
Originality? You mean iteration right?
An example, i clicked on the above link and assumed i was on the website Medium, but then i saw that he was the creator of svbtle, so i decide to check it out, assuming it might be a fashion site, then i realized that svbtle is the site i was on. It seems like the only place seeing any real product differentiation and innovation is the hardware space right now.