Janna can peel from ANYONE. ANYONE. I would rather have Janna for escaping than Sona anyday for almost any situation that could arise bot lane. The only people who will be poking a Kogmaw is a Cait, and it isn't that difficult to migate incoming damage with a shield. Honestly HOW often is it that bot lane becomes a 2v2 deathmatch? Bot lane is largely a farm fest unless a jungler comes in for a gank.
Our opinions our different and not likely to change though so yeah.