One could reasonably ask of such a poem, if it is built on boring, clichés like the example, whether or not it is technically good at all. Suggesting that you can ignore the lines and simply focus on the poem begs the question, of what, besides lines, makes up a poem.
You don't need to bring academic excellence to your reviews, but you do need to have already established for yourself a general set of standards with which you evaluate writing in general, your own and that of others. A poem under review would either meet those standards, or fall short. It is your job as the reviewer to explain the standards on which you base their assessment and leave the poet to make their own determination as to whether the comments apply or not.
Simply saying "I liked this," is no more helpful, or useful, than saying, "I didn't like this." In both cases, there are reasons for your reaction. You have an obligation as a reviewer to be clear what those reasons are, and, if need be, modify them to fit the piece before you. If you are expect to teach with your reviews, you must be equally open to learning.
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If voting made a difference, they'd outlaw it