I mean I do agree that website doesn't "look" like a website that is a multi-million dollar company website, and it is basically give or take the same design as what it was 10 years ago, with only a few minor changes, I do agree that it needs an overhaul of design changes.
Well, if you look at the site of the best investor in the world, it looks like it's on ftp or something. It's laughable:
https://www.berkshirehathaway.com/So, if freebitco.in has a business that is doing very well, with increasing revenue every year, I don't see why they have to change the design. What they have been doing over time is implementing more functionalities, some of which worked and stayed and others didn't (I'm thinking of cloud mining for example). So I don't see it as a priority to change the design.