Sitting in a recliner can be bad for your health if you sit in the recliner for too long without getting up and staying active.
Sitting in any chair or even on the couch for too long is not good for your health and you need to stay moving and active if you want to stay healthy and prevent heart disease, strokes etc.
Moving around is very important for healthy bodies so stay as active as much as you can if you want to stay healthy.
But there's nothing wrong with relaxing in a recliner or a day or so after a long hard week at work.