On moving away from mainstream/centralised/closed-source software
- "The software is inconvenient to use"
This is frankly not true in many cases. It's because the software is not familiar that people say this. Though there are definitely cases where it is true, but those are things that can be worked on - and will be if there's more interest to drive it.
And, to be clear, it's often more convenient than mainstream software, in little ways you didn't even realise were possible.
- "Not many people are using it"/"there isn't much content there"
If you can't see why this is obviously stupid, your use of a (pocket) computer is probably a liability, and I recommend deleting all your online accounts, selling your (pocket) computer, and going back to doing things in person.
If the above is relevant to you and you haven't stopped reading to go off and write an angry email to me for insulting your intelligence: Reminder that there was a time when Facebook, Twitter and YouTube were not used by many people, and look where they are now. How did they get there? People started using them. This isn't a real objection.
- "It's difficult for my grandma/little cousin/etc. to use it"
This one tends to crop up most in response to self-hosting things (eg. federated nodes). And while there is truth in the idea that not everyone needs to run their own software, everyone should at least consider it, and tech people should definitely offer their instance to their friends and family. Because it's actually not that hard to use. It just takes someone familiar with it to teach and answer questions. So maybe, instead of complaining on someone else's behalf, be a teacher.
- "It's less reliable"
Major services have outages too. Sometimes beyond their control (remember that time Cloudflare accidentally blew up their entire operation? - I'm actually not sure that link refers to the right incident, the one I recall was closer to a day long). This is actually worse than the case of a single (or handful of) node(s) in a federated network going offline, because it affects the entire service instead of only one small part of it. It's true that nodes sometimes disappear permanently, and that this doesn't tend to happen with major, centralised services. But it does happen with minor centralised services. G+, anyone?
Oh yeah remember this
Some other variants of these arguments:
"It's human nature to prefer convenience" -> So's stealing your brother's toys. Really, you're just lazy.
"You'll never get popular appeal" -> You aren't everyone. You're lazy.
If you have some argument that isn't in the above list, read it again, because chances are I sent this to you to read the part where I already addressed it. But if it's actually not on the list, fix that.