MyBB Community Forums

ok guys, my friend is planing to open a website and I need your opinion now.
What do you think about this idea : a website to express the own opinion of something. 
In this website you can post your own opinion about everything. For example you can post your opinion about world events, or your own opinion about certain things. The hashtag is used to specify the subject and then you can write your opinion about it. Other people can read all the posts, and there will also be a list of popular topics.
You can choose about what you wanna write. Here an example :
Imagine someone wrote his opinion about one direction, and as a hashtag he used #opinionofonedirection.
Other people can see it, and they can also post their own opinion about one direction by simply using #opinionofonedirection as the hashtag .. 
People can see all the posts which has been written with the hashtag "opinionofonedirection"
People can also create their own topic by simply using a new hashtag .. for example, you wanna post your opinion about school .. then you post #school as a hashtag and you can post your opinion ... Everyone else can read it, and if they want to write their opinion about school, they can also write it by using #school as a hashtag.
There will be also a list of popular / recent topics. 
And of course you can also like the posts of other people, and everyone has their own profil and people can read all the posts of a user .. And there will be a following-system, like here on ask.fm
It's kinda like twitter, but just with a focus.
That would be the modern way to express the own opinion about anything!
What do you think about it? Would you join?
Thank you!

I wouldn't join because it is way to broad. A forum needs a specific niche, that isn't overused. This hash-tag is just a copy of Twitter. it just sounds like your friend wants to start a copy of Facebook and Twitter rather than a new and exiting forum.

Forum? he don't want to create a forum dude ..
it's a social network!

Too similar to twitter.

but in twitter you are just posting what you are doing right now ..
you can't discuss about various things or just post your opinion, because in twitter you can only post 140 letters.

Isn't every form of communication about expressing your ideas? Otherwise there would be no need to communicate. On this forum opinions are regularly expressed and debated even.

yeah but many people are too lazy to join just in forums .. many people just want to post their short opinion about various things and they also want to read just short opinions .. ^^

That's twitter, facebook, pintrest, reddit and well still the whole internet. As I said any form of communication (not just forums).

but these social networks are not focused on discussing in a fast way

How is twitter not focused on discussing in a fast way? They limit you to a couple sentences basically. I'm not sure how you could make it faster.