I can understand several reasons why someone with significant bodyfat should leave gear alone. Firstly, you need to get your diet right and training in order to get the most from AAS. Secondly, AAS are more effective if you are leaner (mg/kg logic, theres a study somewhere that backs this up). Thirdly is the health aspect. Apart from these reasons, though as long as you are not some training newbie, I can see reasons why gear would actually be a good idea for someone with such high BF.
High bodyfat = negative hormonal environment + excessive calories.
Tip the hormonal environment the right way, and as long as you count your protein someone with really high BF will have NO problem with calories, and with the right trainer will likely blow the fuck up on gear. It will also be MUCH easier to lose the bodyfat with the extra muscle mass in the future. Am I missing something?