I believe we already define a Reason if the operator encounters an error. See the following from the cluster storage operator. This is in release-4.1 and subsequent versions:

 	// if error is anything other than unsupported platform, we are degraded
	if err != nil {
		if err != unsupportedPlatformError {
			degraded := configv1.ClusterOperatorStatusCondition{
				Type:    configv1.OperatorDegraded,
				Status:  configv1.ConditionTrue,
				Reason:  "Error",
				Message: err.Error(),
			}

I have submitted https://github.com/openshift/cluster-storage-operator/pull/46 to include default Reason strings on the other statuses.

Verified with:  4.2.0-0.nightly-2019-08-26-202352

$ oc get co storage
NAME      VERSION                             AVAILABLE   PROGRESSING   DEGRADED   SINCE
storage   4.2.0-0.nightly-2019-08-26-202352   False       False         True       56s

$ oc describe co storage|grep Degraded -B 5
    Type:                  Available
    Last Transition Time:  2019-08-27T05:47:36Z
    Message:               storageclasses.storage.k8s.io is forbidden: User "system:serviceaccount:openshift-cluster-storage-operator:cluster-storage-operator" cannot create resource "storageclasses" in API group "storage.k8s.io" at the cluster scope
    Reason:                Error
    Status:                True
    Type:                  Degraded

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2019:2922