Even though I come from a 16 man guild, I would like to drop my two cents here.
Let's assume that we tracked SM progression. Let's also assume that SM was not easy. Would we be able to skip bosses there? Nope. I think HM and NiM share a lockout because they dropped the same gear back in the day. Now they do not, but I do not think Bioware has thought to change that. As a result a situation has arisen. I think a progression model that favors competition should be used. You must kill the previous boss to get credit on the current boss. This does allow you to skip and see the content or get gear. It does not allow you to get credit for cutting corners.