My wife does not know your dog

You're a considerate person

, so I know you'll understand where I'm coming from here. This isn't about you.
This is a message for people who are mystified and offended when their "cute doggie" scares a stranger by jumping on them.

My wife has a phobia of dogs and cats. The reasons and story behind it aren't relevant here, except to say that is an immutable fact: her reaction to the animals will not change, regardless of size, type, or familiarity.

We like our walks, and so we regularly encounter folks walking their dogs. Most are considerate, and control their excitable animal as they pass strangers, but fairly often you meet... them.

You know how it goes with these types.
Their dog makes a beeline for every stranger, often just to take a sniff, sometimes to jump up on them as a greeting, rarely to go for an attack. And the owner just lets them do it.
A stranger cannot reasonably know which of those it's going to be, given they don't know the dog or its temperament. And for someone who jumps out of their skin at the very sight of a dog, it's terrifying.

From there, the empty platitudes flow:
"Oh don't worry, he wouldn't hurt a fly!"
"He's only a little dog, don't be scared!"

These are what really drive me up the wall.

We don't know you.
We don't know your dog.
The fact is, even without a phobia, that situation is alarming, and your reassurances after the fact didn't change that.

Oh here we go

When this is explained to these types of dog owners, often it's defensiveness that flows next:
"That's your problem, not mine!"

They behave as if they are not responsible for their actions, and they try to put doubt in your mind that they were in the wrong. But they were.

To be as charitable as possible, maybe they're just hurt that someone could think their doggie was capable of violence. People form real, tangible connections with their pets, so it's conceivable that they're reacting out of offense.

But let's be less charitable.

It's an animal.

It doesn't have the level of agency, consciousness, and self-control that we are capable of as humans.

Ultimately, it is not responsible for what it does: its adoptive parent is.

We do not blame the animal for rushing towards us. We blame the owner for not holding it back, or for not keeping it on a lead, or for failing to train undesirable behaviours out of it.