I actually worked for Jessops a little over 12 years ago. If you shopped in the Shandwick Place, Edinburgh branch, then you probably saw me.
Jessops was in a poor state even then, they were very badly run, and it continued to get worse from there. They stopped selling 2nd hand goods which had a much bigger profit margin than new, as it they wanted a 'new and modern image', totally ignoring a huge customer base.
Why would you bother going into a shop when you can get it cheaper and easier online? This isn't a photography problem, it's retail in general, rents are a part of the problem, but the main cause is the internet, and I don't think there is anything the retail industry can do to change it.