This should happen, its a no brainer now we have got the land behind the Kop. As has been said, its extra revenue for the club and crates a space for those that want to use it, such as families, and could be more accessible for fans with disabilities, as alternatives to the rammed local pubs. The non-match day revenue opportunities are there too, such as away game beam backs, hire for private parties and events etc.
For me, it would need to be a well priced and quality product, which unfortunately it probably wont be, but we should be looking to work with different local independent street food vendors, put on some unsigned Sheffield bands, have local craft beers on, screen the early kick off, have games for kids etc.