There is a commonly held assumption that poetry is about finer feelings, the personal expression of profound emotion and even that, perhaps somehow, poets have finer feelings than most and that is why they express them. It is presumably a Romantic invention, from when the artist was released from the rigours of discipline to swoon and indulge themselves in sweeping gestures and melodramas of heightened awareness.
While we owe much to them, we also still suffer from the hangover of their excesses.
Geoffrey Hill assured us a few years ago that 'poetry was not expression'. But, thankfully, we are not all as austere as he is. On the other hand, someone else's love, grief, rapture or anxiety is often a lot like our own or anybody else's and not necessarily of interest to us. We know about it already and it is somewhat presumptuous of a poet to think that we might be interested in theirs. We can be just as self-centred as them and only take from them those things they say that correspond to our own experience.
There is no reason to believe that a poet's personality is any more captivating than a reader's and I'm sure in many cases it might be less so. So although I'd always want to swerve the temptation to suggest any manifesto for poetry, I would like to speak up for the modernist idea of impersonality. Although the poet is welcome to be present in their own poetry should they see fit, there are many advantages to be had by not being present, or at least removing oneself as far as possible from one's poems. It may not be an impersonal poem at all and so 'impersonality' can be 'donned' in Thom Gunn's phrase in On the Move. The least you can do is pretend not to be there.
What poetry is about is the words. Painting is about the paint and Music is about the music. It may or may not mean anything but what it means is not the most important thing, not what makes it potentially of interest and not where the 'poetry' is. Poets who think that their poetry is all about them are likely to be the first to come unstuck.