You don't have to believe me, just google "are lift blocks bad" and thumb through the thousands of posts about lift block failures.
Ok but you can do that with just about anything...go to google and type "are guns bad?" and you'll get nothing but "guns are bad"; now type "are guns good?" and you'll get nothing but "guns are good".
Typically people only write extensive reviews or articles on something that they view as either very positive or very negative. Sure, maybe lift blocks are a bad idea when the axle is experiencing forces much greater than the average axle experiences (like when towing a large trailer or being a prerunner), but for the average daily driver 2" blocks won't be much of an issue.