Arrgghhhh!!! That's very very different from just deciding you don't want to work hard enough to continue the rules you've already set up for yourself. It's all too easy to claim you're being expressive when you're really giving in to easy decisions.
"There's pepper in this chocolate pudding"
"Yeah, I set up an expectation and then broke it. I'm being expressive."
To be clear, I never said that in case you're implying I did. I don't know those crazy metric terms, I've never learned them. And I definitely don't think we need to stick to or even know any of them really. They seem pointlessly academic to me.
My definition of "craft" is working hard to ensure the lyrics are most effective at doing their job. While a well-crafted lyric doesn't need to adhere to a pentameter or structure or anything, it DOES need to have been carefully thought-through and chosen after careful consideration. It has to be WORKED ON. It's in the eye of the beholder to a certain extent. People like you and I, for example, may wince if someone rhymes "tree" with "family", whereas someone just starting out might not notice that. And yet, perhaps we're both typing this in rooms with rugs we bought for $69 at Ikea, while that aforementioned beginner lyricist, who happens to be a rug aficionado, wouldn't be caught dead with one of those in her house. We think she's being overly geeky about rugs. This $69 one is pretty and serves the function well enough, but she's got a finer tuned eye for rugs and sees all kinds of reasons the Ikea rug is decidedly inferior. She just can't understand how we can live with those cheap rugs. Everybody's got something they appreciate the fine-tuned craft of, and we're here in a songwriting group where we are invited to offer critiques, so there we have it.