To answer the original question - I ride with earbuds all the time. It helps mightily for my motivation on long rides. It's not something I recommend to new riders because it takes practice and you may have to change your riding style somewhat. It's quite possible to ride safely and responsibly with earbuds, however.

And as a gentle reminder - putting earbuds in doesn't automatically turn an otherwise attentive rider into a self-absorbed zombie weaving all over the place and paying no attention...