On the one hand you really feel for him because it seems increasingly clear given the powerful painkillers he's popping (details are still emerging and at least one may be illegal in the US) that he is in a lot more pain than he lets on. Perhaps this whole "I'm feeling great" spiel is either fantasy or just BS (or the drugs talking). Perhaps golf is all he has and the chronic debilitating back pain, much like a concussion in hockey, is destroying him physically and mentally. Perhaps all the fame (he's still a sporting icon) and money (he's made $1.65 billion in his career and is the second richest athlete in history) are useless without health and family.
On the other hand. Drugged driving (whether the drugs are legal or not), which also falls under DUI, is now linked with more fatalities in the US than drunk driving. So yeah, equally irresponsible.