It's very first world centric point of view. I doubt some of these commentator claiming whatsapp being down is good for the society have ever been outside of the first world and have seen how it actually helps people in need.

But doesn't that mean it will be easy for the SMBs to move to any replacement service?

At the cost of losing customers, is my point :)

Uff, I see no reason to smile about it.

Maybe these business will diversify their communication mediums because WhatsApp is down - seems like a good thing for society.

Do you even know who these business owners are and what kind of life do they live? These are the guys that don't have a solid roof over their head, struggle to meet their daily needs and might have to sleep hungry if their day's sales weren't good. Diversifying is the least of the things they have to worry about. Whatsapp allowed them to reduce friction when it comes to communicating with customers, it helps their sales.

What might be a good thing for society in the first world doesn't mean it's necessarily good thing for society in the third world.

I reject this logic - it's an argument for sustaining the status quo at all costs.

Facebook is the most user-hostile tech megacorp, and they will inevitably harm these businesses you care about. The sooner the bandaid is ripped off the better.

I mean, sure, status quo can / should be changed - but you want to get to a point where a changed status quo is sustainable, and you're not going to get there by simply removing existing options. It doesn't change the incentives people have for preferring to use the platform, namely the pre-existing widespread penetration.

You want to dislodge Facebook, you need to disrupt it / curtail its monopoly.

Companies diversifying their communication platforms is the disruption.