It would be pretty interesting to see QF's data on these tail strikes, and exactly how many there have been in total. There are a plethora of possible root causes.
Is there actually a pattern emerging?
Any change in procedures?
Any change in procedural training?
Any change to standards?
Is weather or location a factor?
Changes in rostering - fatigue?
Operational pressure?
The ATSB report will no doubt be interesting. And there is never only 1 contributing factor.