Why are people in r/weed so heavily in denial about the fact that you can become physically dependent on weed?

I've noticed time and time again there's all these people in that Reddit that deny that you can get withdrawal symptoms. They call it bullshit, ask if I'm taking opioids. Do these people not smoke weed? Are their bodies programmed aliens to just constantly accept marijuana and never withdraw from it? I don't understand how these guys dont realize you CAN be physically dependent, and they are so incredibly insistent that it's only psychological. My horrible withdrawal symptoms that make me shake, unable to sleep, and have a constant racing heart, among other things, say otherwise.