The ATSB is pointing the finger at the training technique of thinking "flare" at 30 ft. Barking up the wrong tree. That is an entirely appropriate flaring technique for a B737, particularly for new pilots. I suspect that none of the authors of this report have ever flown a B737.
The report points the finger at the difference in expected technique and the PFs decision to use a different technique on one flight after being taught another technique. If Boeing says that higher flare heights will result in hard or bounced landings you are pretty much stuffed if a bounce or hard landing occurs, legally, if you vary from that technique. So the ATSB analysis is correct even if in practice you might have easing procedures that work in 99% of occasions. If you vary from a manufacturers procedure you better hope that they agree with you when it goes wrong, which they won't as their documents are written to cover their own arse. If you wish to vary the procedure you need to have it approved by the manufacturer.
Regardless, the late flare was not the root cause of the hard landing*. The initial touch down was not recorded as hard, it resulted in a 3 ft bounce. This needs to then become a bounce recovery. The hard landing* (if it even was one) was actually the result of bounce recovery technique, which is not addressed by the findings of the report at all.
That is addressed in the report, the fact being the bounce resulted from the initial landing, so the initial landing technique was the root cause. Bounces and such in aircraft like this are far more an issue than simple aircraft bounces due to the unknown factor of what the drag systems will do, such as whether the spoilers activate or not.
*Boeing provides information (not addressed in the ATSB report) that a QAR report of a hard landing and associated G-loadings are not accurate. The most accurate assessment of a hard landing comes from the crew, and the report states that neither crew regarded it as a hard landing. So this report could actually be all about nothing other than a bounce which was recovered.
The FDR recorded the second touchdown at over the 2.2g limit that constitutes a hard landing. I'm not sure there is any aircraft maintenance manual that will conduct inspections on crew advice only, the crew advice will result in a FDR analysis that will determine what maintenance action is required. Considering the cost involved in inspections of this nature and the downtime I would suggest the FDR data is paramount in deciding what is done. I Understand that QARs can be less accurate than the FDR, however I would suggest the Boeing advice is more to counter any understatement of G loadings from the QAR, ie the crew feel it was a hard landing but the QAR says it's not. Imagine the report on a 737 that had a landing gear structural failure within 10 cycles of a QAR reported 3 g landing and the crew stated it was not hard so no inspection carried out. We all know what almost happened to the VA ATR that had an improper inspection following a turbulence and poor control input event.