Wouldn't the main point be more like "Stealing Thunder is effective, but it has some limitations?" Why aren't we including the bottom limitation point?

I am very grateful to 7Sage!! I used to struggle with RC. I just started studying RC with 7Sage today, and I got 15/15 on the practice!! I used Blueprint for several months, but it didn't help. 7 sage did more for me in 5 hours than Blueprint did in 3 months :)

I have trouble seeing how the last sentence indicates author's opinion. Couldn't it also be just Turner's opinion?