Are you serious, Sovalou? Always these same illogical arguments arguments, I swear I am going to melt because of the amount of stuff on here. Stuff like:

You can clear it with a SMN - therefore it's ok
Every class has it's downside - therefore it's ok
You have downturn on every class - therefore it's ok
...

I'm going to say it once again. Summoner's DPS is in every front weaker than BLM. Weaker ST, weaker AoE and weaker burst. It has weaker utility and that makes the Black Mage far superior to SMN. The amount of input and skill you need to perform on a Summoner is a lot higher than it is on melee and Black Mage at the moment. Not that SMN is a difficult class, it's just hard to get high numbers. It has to be absolutely perfect.
That's the problem. Summoner is outshined in every single aspect by other classes. There is no reason to play it in endgame content and that is a problem. Why is this so hard to understand? Even SE acknowleged that SMN is weaker than all classes and that they are looking into it