Are you aware that disclaimers of liability are not considered valid contract terms in most scenarios and legal jurisdictions in western countries where software is likely to be used?
Do you believe that you can disclaim liability for negligence such as carelessness or a failure to thoroughly test? How about for intentional malicious acts? Courts in the US and commonwealth nations at least don't allow such disclaimers. What about other sorts of liability? Do you know the differences between direct, consequential, special, incidental and indirect damages?
The reality is that in enough jurisdictions to matter, authors can be held legally liable for bad code they create no matter whether they have a liability clause as a condition of licensing or not. Forming an LLC or corporation won't shield them either if someone wants to sue. The only protection in these cases is maintaining E&O insurance.
If I use GPL, BSD, or any other licensed code that disclaims liability, and the code is flawed because the author was negligent, I can sue the author for damages and I can win. The disclaimer does absolutely nothing.
What purpose then is there in cluttering up licenses with useless clauses?
I use the WTFPL too since it is the most free license and easiest license to understand. It also deals with the non-issue - but common complaint - that "public domain" does not exist in some backwoods third world jurisdictions.
I also use the zlib license which is very similar to WTFPL. It has restrictions against misrepresentation of origin, which in practice only affects plagiarists, so isn't a substantial limitation. An advantage of the zlib license over the WTFPL is that it can be used in "professional corporate" environments where suits have a hissy fit if they see the letters "WTF" in a license, saying that any use of that term is in some way immoral, while conveniently ignoring the fact that they personally are secretly cheating on their spouse, engaging in insider trading, embezzling, looking at donkey porn, and drowning kittens in their spare time at their palatial estate.
These two licenses are the ones that preserve actual freedom, unlike certain others that propaganda artists often apply the word "freedom" to, using a definition that exists only in their own imagination and is not consistent with the commonly accepted understanding of the word. These licenses are also comprehensible and far less ambiguous than certain other licenses as well. The zlib and WTFPL licenses are good and useful licenses that are worth consideration by any developers looking to license their code in a way that maintains as much freedom as possible.
