The question is "why"? Students have a choice to read the poems in an interesting way, or a boring way, and many are opting for the boring way. With rare exceptions, most students are walking to the front of the room, reading the poems in a same sing-song pattern as a Dr. Seuss book, and then promptly sitting down. While nerves and content play a role in it, I think the biggest reason for the boring-down of poetry is the lack of any acceptable models to the contrary.
Despite knowing better, the average person, when asked to describe a poem, will simply state that it rhymes. Maybe that its short. If those are really the only things that make a poem, it's reasonable students would find them boring and dismiss them as little more than glorified song lyrics. But of course, poems aren't limited to this model. As written are just words but when spoken and read become something more. In order to make this reaction occur, one has to understand the final product. I think that's where many students are getting it wrong. You can't just read a poem slowly or sadly, or Britishly to make it powerful. You have to make it real. Only then will you be able to shift from "boring" to another more interesting choice.