I realize that conventional wisdom is that rhymers won't sell, but in fact rhyming books are published all the time. There are very few editors who refuse to look at them at all. Publishers dissuade people from submitting rhymers in marketing guides because the truth is, most people who think they can write in rhyme actually can't. (Not referring specifically to anyone here, of course--I have no idea about anyone's writing here.)
As for the distinction between rhyme and lyrical language, they are two different tools in the writer's toolbox. Lyrical language sounds mellifluous, lovely, musical, beautiful, imaginative, unique. Rhyme rhymes. Rhyme may be a part of lyrical language, but is not necessarily part of it. Lyrical language may be part of a rhyming manuscript, but not necessarily so. A rhymer might be rough-and-tumble, crazy, word-play, not really lyrical at all, but still good. A lyrical manuscript might not have one bit of rhyme in it, even as it uses assonance or consonance for different effects.