The site doesn't have an SSL certificate so many browsers will tag it just for that. The HTML code does run a couple of small scripts however if you use firefox with no script it works fine.
Adding an SSL certificate either costs money or requires a degree of expertise that may not be available. Also the site has been around quite a long time and the tools that were used to build it don't exactly create to the latest HTML standard. The internal debate at the moment is what to do about it and who could do it.
Cheerio John