Yeah true. I thought about this a lot and I think it is an expression of some inner nihilism and a self-destructive habit. By trying to focus on something creative and doing a good job, I can put the nihilism at bay and thus my desire to self-destruct through drinking is reduced.
Not sure how much science there is, but I suspect that a lot of drinking turns out to be self-medication for depression (and/or anxiety). If so, it's obviously not ideal, but it may be that in some cases there is no clear superior alternative.