I am not entirely sure what you mean by "pattern", but in any event I think the word "obsession" is a little strong. Some of the people here are simply trying to learn about one of the most fundamental aspects of ALL poetry: stress and rhythm - and to my mind that is really great because without such understanding you are severely handicapped in your poetic advancement.
I guess it all depends what you meant by "pattern".
If you are referring to the simple counting of syllables then I would be inclined to agree with you. I have never been a great fan of syllabics - imo they don't have a great deal to do with the rhythm of English.
On the other hand if you are referring to stress patterning, i.e. the way in which different emphasis and length is assigned to different syllables, then I completely disagree. In my view, whatever poetry you want to write, whether it be form poetry, rap, spoken, free verse or any combination, you definitely need to have a good grasp of poetic meter and the way that sounds interract.
If in order to appreciate stress and meter you have to obsess a bit while you are learning, then I think that is fine.