My take on this is no they don’t. As long as they are truthful they only report on the quality of the product and prevent many people of spending a lot of money from losing it by buying something that doesn’t work.
If your product is shit your company does not deserve to be shielded from the backlash, this is the core of (classic) capitalism after all.
While this is possible for a couple of years, it is definitely not sustainable in the middle term. If that was true, then Ericsson and Blackberry would still have the biggest market cap in smartphones and GM, Ford and Chrysler would be the biggest car companies in the world.