You’d never believe how much time I spend with my college freshmen, unteaching them what they’ve been taught in high school. For instance, they tell me that you should never use the pronoun you in an indefinite sense, meaning someone or one. If you do, you’re a stylistic redneck.
“One must lift the tip of one’s nose to the cup, just so,” says Monsieur Lemonnier, removing his pince-nez for the purpose, “and flare one’s nostrils so as to let the bouquet of the wine enter into one with the most effective effluvia.”
“Enter into one what?” says Bobby Joe.
The indefinite you is perfectly fine for almost all kinds of writing. Oh, not for the description of scientific experiments, I grant. “Well, first you drip this red stuff here into that there tube”—I don’t think that will do for a journal article. But for popular writing, and even for conversational writing admitting of a high intellectual tenor, the use is admissible and often preferable to the alternatives. In those cases, it beats the heck out of all those ones.