Weird? I don't follow. I understand it might not be the most effective way to play. But i don't think it is in anyway weird for some of us to not particularly want to be associated/tied to so many orgs.
To many people and to much going on and possibly to many obligations to come out of it. I would much rather stay in my own org of 10 ish people ( close gaming family ) and go about our business and potentially after a few months introduce a couple of people at a time and see if there is a potential for us to build a small business to slot into the bigger picture.
That's all well and good but you're looking at orgs the way people traditionally look at clans/guilds in other games. That's not the purpose of an org in Star Citizen, they aren't that rigid and are meant to be more flexible. Much like in real life you might have a gym membership but also be a member of a shooting club, a rower, into a car owners club etc. Some you'll take more serious than others and in some cases you may not consider yourself "loyal" to any of them in a meaningful way.
That's why I mention taxes, if people aren't loyal to an org they won't want to accept any tax that's imposed on them by it, even if it's extremely small on principle if the leadership area sitting gathering money for simply having founded it etc.
We've got an upper membership limit (150 presently) with no plans of raising it but as there's a core of us who play together (around 10) and an extended group that are in contact with me regularly in one way or another (another 40 or so) I actually think our number of 150 is likely to be about right if I want us to have a UK centered group who are on most UK evenings and able to do something together if people want to.
There's no reason a dedicated group of 10 couldn't do that themselves though, but as numbers drop and people stop playing that quickly becomes a problem. That's where having a few additional people around helps fill the gaps whilst new, good members are recruited.
Initially this'll be the main benefit of having membership in several orgs, you'll always have someone to talk to and play with if you want who are in a group with you and are presumably there for the same reason - that's assuming they aren't infiltrators

and obviously those sharing org membership with you are likely to be known to others who you trust or have some form of reputation with the org leader which allows them to be members (this is where large orgs fall to bits as members cant trust each other to the same degree IMHO).
I'm in 4 orgs:
https://robertsspaceindustries.com/citizens/Raumarik/organizations
1 I founded, 1 is a PAGAN members racing club and the other two are meaningless to me but I'm in there our of general interest. If the linux group or operation pitchfork try to levy a tax, I'll be out as quick as a flash but otherwise I'm happy to be there and I do talk to members of those two orgs regularly on the forums.
I'm not saying being in a small exclusive org is bad, I simply personally think it's a restriction without purpose (in other words - a bit weird).