I would disagree.

A Blockchain is merely a tool like others. Yes, it is decentralised, meaning that businesses don't govern them for profit. But it is not the business which wants profit, but the humans behind them.

If regular free reviews can enable emotional rants and misleading reviews to dominate the place simply because of the users who are attracted to them, the same can also happen on the Blockchain. The blockchain is dependent on the users in the end. Take a look at Steemit and all the Upvote bots and self-votes. Steemit still has potential but is on the path to corruption.

It may provide honest reviews as long as it has a manageable level of users, but once the place becomes full of them, it shall be a dog eats dog world with competition which touches the sky. People will start lying and manipulating just to gain more out of mentioned incentives and followers. The second problem would be fan wars with fans of authority figures being loyal to their idol and boosting them regardless of the stuff they write.

Stuff like Youtube and Instagram are pretty open. They don't govern much. But the same happens with them as well. It's just human nature and is inevitable. The only difference is that you'll gain money from what you write based on how likeable or influential your post is. And that just opens up a whole new plethora of problems.