Just looked up "Law of Attraction" on Amazon - and found that it had some "competing" books, but also a fair number of books which were coat-tailing their sales onto the hit of the original ones.
The funny thing is that they were getting just what they were espousing - a slightly critical set of readers who would like to believe in what "The Secret" was saying, but weren't actually able to believe in it.
And this is covered in that movie, where you are told that this is really the reason it "doesn't work" as well - you really, really get exactly what you believe in and work for.
Now some have tried to get these teachers into that realm of "if you just think a certain way, it will happen" - while the Secret is very clear that you have to take action on your own, based on the intuitional responses you get after you hold a very clear picture of what you want.
Of course, the proof is in the sales. Critical books usually don't last as long as the bestsellers. Check out "Think and Grow Rich" sales and you'll find that they are continuing today just as ever - but you don't see a bunch of books criticizing this 1937 classic today as "unworkable" or "cultish".
You do find people who have changed their lives by reading it - Earl Nightingale (founded the motivational recordings industry and was very well off when he died), Bob Proctor (apparently very well off today), Robert Collier (known philanthropist worth 1/2 billion at his death), and so on. If you follow his book (not very much different from the precepts found in "The Secret") you can have success in your life.
If you doubt it, it doesn't work for you.
In Secrets of the Law of Attraction, the second book excerpted is Bristol's Magic of Believing. And I find this for good reason - his whole book was devoted to exploring how a person's beliefs will shape his world.
While the first book excerpt was Troward, the third was Genevieve Behrend - who had a chapter entitled, "How I attracted to myself $20,000".
So the critics are actually hanging themselves with no needed help from the rest of us.
The positive thinkers win - continually - and just as Wattles said, "... and the riches they receive will be in exact proportion to the definiteness of their vision, the fixity of their purpose, the steadiness of their faith, and the depth of their gratitude."
- - - -
Some people are making money online (apparently) by setting themselves up as expert debunkers - and attracting people using others' good names ("Exposed - Find the real truth about [famous author] - click here!)
But remember, that law of attraction works all the time, every time. If you listen to critical people and believe them, you will get more critical thought into your life. Sure, you can check them out for contrast (things you don't want in your life) but don't get into any sort of routine critical thought. Your life has nothing in it now that you didn't think about earlier.
Critical people lead critical lives. Postive thought (followed with positive and effective action) will result in positive results in your life.
It's too easy to criticize. The harder thing to do is something positive to solve the problem.