This may well be correct. One thing that I would note is that in female sport, the best athletes seem to play the sports which provide the opportunity to perform at the elite level. i.e. the participants often haven't played a particular sport since childhood so aren't rusted on to any sport, but will gravitate to those sports which provide high level competition - for example the gold medal winning 7s team attracted athletes from a range of sports. Female sport also seems geared to playing more than one sport at the top level e.g. Ellyse Perry who represents Australia at cricket and soccer. It's been decades since a male elite athlete could even consider playing elite sport in two sports.
The ability to change sports at a later age and play two sports at the elite level will disappear as the professionalism increases.
Professional opportunities are increasing quite rapidly, particularly with the AFL Women's League which I believe will pay players much better from next season.
The pay for netball players is also increasing.
Prior to this, cricket and women's rugby 7s have been the only good options to be full time professional sportspeople for women in Australia in team sport.