While there are certainly conditions in which these bacteria might thrive, their inbuilt inefficiency -- secreting large quantities of energy-rich alcohol -- su

While there are certainly conditions in which these bacteria might thrive, their inbuilt inefficiency -- secreting large quantities of energy-rich alcohol -- suggests that, in their current form, they'd be relatively easy to outcompete. They don't seem to have any particular advantage in an environment where their unique characteristics are not beneficial -- and very few environments would seem to fit that bill.