when creating a pod with nothing shared and without infra

here is the full commands

podman pod create --name=pod_test --infra=false --share=
podman network create pod_net
podman run --name=test_web80 -d --net pod_net --hostname web80 --pod=pod_test busybox httpd -f -p 8080 -h /etc
podman run --name=test_web90 --requires=test_web80 -d --net pod_net --hostname web90 --pod=pod_test busybox httpd -f -p 9090 -h /etc

podman pod ps

9a894043a1e1  pod_test        Running     18 seconds ago              2

if we replace 

podman pod create --name=pod_test --infra=false --share=

with

podman pod create --name=pod_test  --share=

podman pod ps

would display Degraded

5f2458ba5eac  pod_test        Degraded    18 seconds ago  a3a4ca1b8e4d  3

if we remove --share=

it would complain about multiple hostnames

what do you suggest?

and why systemd care about infra?