Look at it this way: there IS no "bad publicity". (Swap 'publicity' for 'traffic'.)
Reviewers give their opinion. It's allowed in a free speech soceity like ours. You can say "I hate Pepsi and no one should ever drink it!" without ever tasting it. Oh well, freedom woohoo!
Re-design your site, make it responsive. Add HD pictures. Update whatever you can. Then contact the reviewer or review site (politely) and ask them to re-review your site. Tell them you read the original review, took their advice, and now would like them to see it again.
Then move on with growing your business.
