I agree. That's how the legal system works here in the US. And having the law clearly on your side doesn't actually matter much. Judges don't just throw stuff out even if obviously frivolous. You have to defend yourself. It's different in Europe.
There are some legal systems in Europe where the situation is arguably worse.
The libel laws in England and Wales are notoriously plaintiff friendly with the potential for substantial costs awards against the unsuccessful party. There have been several prominent cases of "forum shopping" - seeking to raise an action in E&W to benefit from this asymmetry when the claim could properly be heard in another jurisdiction - and the USA has introduced legislation restricting the recognition of foreign defamation judgements where the speech in question would have been protected by the first amendment.
http://legislink.org/us/pl-111-223
Adversarial legal systems (e.g. in UK and USA) generally require a party to the action to make submissions that the action is frivolous/should be dismissed before a judge will consider whether this is so. This obviously requires that the defending party bear the costs of professional representation to make such submissions, and these costs may not be fully recoverable even if the court concurs that the action was brought without merit. (most common law jurisdictions have provisions for sanctions against a party who has conducted litigation incompetently or unreasonably, this is typically a high test to overcome and not often used in practice).
Perhaps your reference to Europe concerned countries with inquisitorial / civil law systems (e.g. France) where judges have greater initiative and can intervene to halt obviously abusive or ill founded litigation - so perhaps one can then confidently ignore an ill founded or abusive lawsuit. I have studied only commonwealth countries so am not informed enough to give an opinion.
We're up against the human need for recognition / significance again. Somebody with apparently no legal education or professional experience is determined to give their opinion in order to support a proposition that would not be good for Baron or ET. People really ought not to speak with authority outside of their field, and if they cannot be silent at least qualify their statements as being based on other than direct knowledge or experience. Or perhaps indicate their level of experience when writing. For example, I have a British legal education and have done some work for (trial) lawyers in UK many years ago but I do not practice. I agree with Baron's observations regarding the difficulties of publishing reviews submitted by anonymous third parties which could conceivably harm the reputation of others. And I understand the practicalities and nuances where a lay commentator might simply say "if it is not illegal then you have nothing to worry about".
So the better question is perhaps "How come there is no poster ranking on EliteTrader". Again, I think the best improvement to ET would be a prominent place to verify and display the credentials of the poster. As not everyone is able to discern from the content itself. Although most who are worth talking to can and do. Then we could see at a glance which ET members have legal qualifications or experience, expertise setting up low latency trading systems, are profitable independent traders, etc.
, nonetheless a great site, with ratings weighted by each user, some brokers have hundreds of reviews, and spam is being checked for (i.e. brokers trying to prop up their own ranking...)