The second-person "You", usually conjoined with present tense, as in (example)
"You take your mother's wedding dress from your closet,"
appears way too often in poetry drafts, including my own. Contemporary poets seem worried that using "I" is too "confessional" or too assertive. Some years ago poets wanted to be assertive, but currently it's important to seem humble and modest while practicing this most egoistic and self-indulgent of professions.
A "you" implies that there is an "I" but doesn't say so. I say, if it's an "I" poem, please come out of the closet and use "I."
The second-person "you" is technically an address either to the readers or to a specific person the poet knows. The "you" poem very often addresses an impaired, unlovable, absent or somehow guilty person. Therefrom comes the pleasure of using the "you," because you can expose him without naming names. "You" could also be the poet addressing himself or herself, especially regarding a past self such as the one who made a bad marriage. ("You put on the dress and veil/dreading your walk down the aisle to your father" usw.) Why should the rest of us read a poem addressed to your ex or your former self? Please be conscious of addressing poems to "You." It is bad if it is a habit. I catch and correct myself in later drafts.
The other alternative to "you" is the third-person pronoun "he" or "she." Here is where it's clear why the "you" is such an attractive option. Both "I" and the "he/she" demand greater nerve and attention to detail. The "I" should bare it all and articulate the unpleasant truth such as "I didn't want to marry him, but I was pregnant and married him for the sake of the child having a father and so my parents wouldn't harass me." The third-person "She" and "He" indicate people -- characters that must be detailed so as to resemble real people with mixed thoughts, feelings, and experiences. "You" is an outline, a faceless shadow figure -- to the audience. The poet uses "you" to hint at an entity rather than taking the trouble to describe it. It's just easier! The reader must figure out from the poet's dropped hints whom "you" might be -- an ex, a dying grandmother, a former self. I wonder what cultural rule poets are upholding when we could be direct and forthright but choose not to.