I have never seen vegetarian pho...

the thing is, decades ago people would toss any meat they could find into the pot

happens all over the world, tho the Cajun "What's for dinner?" line is my classic

"What's for dinner?"

- Anything slower than us.

quite a lot of options.

I often find the broth way too salty - The Mrs had Tofu and veggies a few days back. She was a fan. Me, not so much...

Unless you’re a Buddhist monk, there is no vegetarian pho.

It’s like ordering spaghetti Bolognese, without meat in it.

The fact that we can expect such things in the western world irritates me.

Perhaps its just me - but I'd much rather have spaghetti in a light olive oil sauce with garlic and veggies - maybe some shrimp if it were a weekend night...

Not any lovers of the heavy red sauce here. My daughter would rather have pasta, butter, cheese. Perhaps a grind of black pepper.

pasta with butter or olive oil (some salt if olive oil), some garlic and parmesagne.

pasta with tomato sauce, meat and parmesagne

They are both very yummy. The second version will give you umami overload (which is not a bad thing).

Spaghetti Bolognese is not a heavy red sauce, it’s mostly meat. There’s very little tomato in it at all.

The point was, pho is all about the broth; the noodles and garnishes are no big deal. The flavor you get from a well-done batch of beef pho cannot be duplicated in any vegetarian dish. Nothing wrong with eating vegetarian, if that’s your thing, it’s just not the same.

I personally love Thai food because of the strong flavors and spiciness, but I can't imagine eating it too often because it's too rich and sometimes greasy. I choose restaurants through https://nicelocal.co.uk/london/restaurants/type/thai/ . Vietnamese food, on the hand, feels lighter and cleaner to me (not all dishes, but most) and usually comes with tons of veggies. For example, the Vietnamese canh chua seems a lot lighter than the Thai tom yum. So, generally I pick Vietnamese because at least I can eat it everyday without getting the sick greasy feeling that makes me nauseous, but I love Thai food too!

Javadog's point was that spaghetti is a type of noodles and that Bolagnese is a cultural preparation of how spaghetti is presented that involves lots of meat.
He wasn't saying it was the only way to present spaghetti; but rather that it isn't Bolagnese without meat.

Point being that in a similar fashion he sees Pho not as a soup with noodles but a cultural preparation that specifically revolves around meat as a key item to the flavor.
Take away the meat, and the cultural dish is removed from being what it is.