The problem for rugby, as for cycling before it, was the doping changes the nature of the sport. When you have flankers with the speed of wingers, and wingers with the size of second rows, the game ceases about skill, sleight of foot and hand, seeking the gap and avoiding the contact - it becomes about seeking the contact, no gaps anywhere and wars of attrition - a direction rugby League (and Gridiron for that matter) went in decades ago - no surprise that RL and US football were/are riddles with steroid abuse, with RU catching up at pace.
Indeed, i wonder do the 'obvious' doping sports - cycling, track, swimming etc - ever feel hard done by when if anything systematic abuse in the oval games are worse.
Hell, its even crept into completely amateur Gaelic football, to much the same effect as spanish soccer. And again, it change the nature of the sport - the 'handpass' game is accurate, but labour intensive, requiring huge aerobic ability - the classic kicking to catch or space game, arguably the more skillful gets pushed aside because the 'handpassers' can now keep it up for 70 minutes and the 'kicking' teams can't run the sheer athleticism out of their legs to allow pure skill to take over.
Luckily, no amount of EPO can prepare you for a hurley struck round the ankles. But since every man jack hurler frankly should be on the anti-psychotics, its six of one, half a dozen...