Why do jobs not want you to come in sick but turn around and chastise you for calling out?

I'm running a 101.0 F fever you do not want me in believe me. I called off this morning and they acted like I committed a war crime. I rarely call out unless I need to and I'm never late. Give me a break I'm dizzy, body aching, chills... I'm useless right now. Hurts to move and my tastebuds are gone.