I wouldn't mind those kinds of book titles so much if they just said "Learn basic [language] syntax in [n] [units of time]". Not as catchy I guess, though.
Speaking as someone who has had to maintain code written by someone who "learned" from these books, I completely agree. What was there was certainly C++ in a purely linguistic sense, but as code it was complete gibberish.
I am maintaining "code" written by person who was given this kind of book and told to build ERP. (This person don't have any previous knowledge on programming, mathematics or even computers)
Well, you can learn the syntax but the problem is when someone says they "know java" usually you care about them not just knowing java syntax, but the pitfalls, many frameworks that exist, general approach to problems, etc.
Just because I know Java + Ruby Syntax + Some stuff on RoR does not mean I am a good RoR programmer, there's just so much more to RoR than the syntax.
I want to see someone completely grok pointer logic in 24 hrs from knowing nothing.