Rate limits not limiting anything - kubernetes

Question

I'm trying to use the istio rate limits to limit access to the service hello.
(1 call per second max)
I used the template from the book info demo application.
This is the configuration I've got so far :
Handler
apiVersion: config.istio.io/v1alpha2
kind: handler
metadata:
name: quotahandler
namespace: istio-system
spec:
compiledAdapter: memquota
params:
quotas:
- name: requestcountquota.instance.istio-system
maxAmount: 1
validDuration: 1s
Instance
apiVersion: config.istio.io/v1alpha2
kind: instance
metadata:
name: requestcountquota
namespace: istio-system
spec:
compiledTemplate: quota
params:
dimensions:
source: request.headers["x-forwarded-for"] | "unknown"
destination: destination.labels["app"] | "unknown"
QuotaSpec
apiVersion: config.istio.io/v1alpha2
kind: QuotaSpec
metadata:
name: request-count
namespace: istio-system
spec:
rules:
- quotas:
- charge: 1
quota: requestcountquota
QuotaSpecBinding
apiVersion: config.istio.io/v1alpha2
kind: QuotaSpecBinding
metadata:
name: request-count
namespace: istio-system
spec:
quotaSpecs:
- name: request-count
namespace: istio-system
services:
- name: hello
namespace: default
Rule
apiVersion: config.istio.io/v1alpha2
kind: rule
metadata:
name: quota
namespace: istio-system
spec:
actions:
- handler: quotahandler
instances:
- requestcountquota
Needless to say that curling the service's ip is still working even when its well over 1 request per second and the limit is activated...
FYI, I used the serviceIP / virtualService (+ gateway).
Also I'm using the "In Memory" version and not the Redis version.
Any help on understanding where the error is would be gladly appreciated !