Serious question : Why would I join a clan ?

I guess I could answer with equally silly question: are you usually happy with your random, blue teammates?

It's always a bit of a lottery with reds...like the typical "not so much success story": you are about to engage a target, trying to corner-peek it...and here comes the db "hello" from the new mm....i.e. something with 4...5 weapon level above yours just jumped on you and evaporated that poor pile of metal you were driving, giving you that instant jump-out-of-the-mech experience That can always happen.
Thing is that when u team up with some fellas from a decent clan, you know what to expect from blues. No potato tashas, no fight over beacon...instead of that a chance for working in teams of 2-3 bots, applying tactics to expose enemy, proper MR support for knifers, etc.
There is also an "advisory" benefit of seasoned players helping you e.g. to balance your hangar.
All in all it's worth it as long as you don't get into team that has demands exceeding your way of playing.

You get to pick your teammates and possibly verbally communicate with them (discord, line). Hopefully Pixonic will fix the matchmaking so you don't continue to get penalized for squading by matchmaker (exception in Top Tier where MM penalties are irrelevant). Talking with experienced players on voice comms can be fun and net you a lot of valuable info fast. Send requests to clans you liked fighting with in battle and feel free to try a few to find the right clan for you. Clan members can send each other gifts that give both the giver and receiver bonuses.

However, there are lots of great players who don't join clans and it's totally optional. Once you get a lot of players on your friends list being in a clan becomes less important. I benefited from being in a clan early in the game and in turn helped out newer members once I became an officer.

Finally, some of us like the challenge of starting and building a clan and the sense of comradely and accomplishment in moving up the ranks.

Try to avoid sending clan requests to the top 100 clans - unless you meet the requirements they post. Good Luck!

Thanks all for your input, it's really an interesting discussion.

Random, you mention we can get bonuses from offering or receiving gifts, could you explain how that works ? Let's say I give a couple of Pins to a friend that starts the game, we both receive a bonus ? Is it a big one (I mean big like 50% of the value of the weapon, or whatever) ? I could understand why a guy would receive a bonus for giving something, but not really why the receiver would receive a bonus also.

In the end I will probably follow B30RLL advice and join a clan. No risk involved. I need to think about that.

And heavypanda, what do you have against Noricums ? It is my favourite setup, I noticed a 3 Noricum on a Leo paired with a Thunder work great ! Ok just kidding here. Having an average hangar (bots level 6, weapons level 6, roughly), I'm afraid joining a clan will make my opposition actually stronger, but like B30RLL said, there is nothing to lose to give it a try.