[Zooey]

I see a couple of problems:
1. Many, many people do not know how to discern what is good from what is bad, in books. Also, Tripp (like others) presents a a Biblical authority. But, you see, the only real Biblical authority is the God Who inspired the Bible. (Hence, the need for discernment).

2. There is always a mixture of good things & bad things in any parenting book. (Or any book about people--we aren't cookie cutters!). If the good "works", or somehow helps you in a particular situation, it is easy that, when you are tired, or sick, or just at wits' end, you turn to the book you liked before. Only this time, it is a different child. Or simply a different situation entirely. [Child #1 had a meltdown (when you were on day 2 of a killer migraine)over something Tripp addresses in particular; Child #2 has a meltdown when you have another migraine, but the child is different, & the situation is completely dissimilar....only, when your head is pounding, & you are seeing the whole world through a haze of flashing multicolour lights, you make the mistake of missing out on the differences.
(It isn't just Tripp, of course. It is that we all tend to backtrack to "what worked before".....and become frustrated when it doen't work this tiem).

3. And then, again, and I know I am repeating myslef somewhat---Tripp isn't the Bible. He may be less egregious in some ways,than some other books, but he is just another ordinary human like the rest of us.

I know others will say all this better, but I hope this helps.