There is a big culture difference as far as ATPLs go between NZ and Australia.
In NZ the ATPLs are something you (generally) need for airline command only. In fact, as there is a flight test requirement, which in 99% of cases is done as a part of a command upgrade, and if one was to do the exams too early the credit may even expire before that person gets a chance to make command. The result would be either having to re-sit them all or to pay out of ones own pocket for a check ride in a pressurised aircraft.
In Australia the ATPL subjects are (generally) needed for even an F/O position at the smallest of turboprop operators. I don't know why, but that's just the way it is here. Perhaps sometime 100 years ago we were stung with a lot of people that simply weren't capable of passing the exams. Who knows! Australia also has a smaller percentage of (ex)instructors amongst the pilot population, so the brush-up on aviation knowledge is probably useful for many. Although, once again, that brush-up would probably be a lot more beneficial closer to airline time then it is for all those doing the ATPLs as a follow-on immediately after getting a CPL.
I think there should be a two-tier ATPL system. One set of exams for freshly minted CPLs and one set for guys that already have the hour requirements for the ATPL!