No. The deference people have to the law as some sort of all knowing all powerful magic spell that can be cast to force silence at any time is to blame. Libel is publishing something you know to be untrue. The truth cannot be libel.
If you want to speak the truth, if you want to act in service of the greater good, you must take the risk that you will attract attention from people who do not want you to speak the truth. And those people may use whatever power they have to suppress you, whether that's judicial or extrajudicial. That's not caused by any specific legal system, it's how people behave.
Investigative journalism is uneconomic the world over. The U.K. has some of the best investigative journalism in the world. The U.K. legal system is far from perfect, but it is wrong to say that in this case, the U.K.'s libel laws (for all their flaws) kept this information secret.
The irony is that the greatest suppressor of the truth is comments like yours which scare people into silence about the truth.