In that case absolutely any hobby that doesn't provide instant positive financial feedback to you is a worthless waste of time.
Time - I spend maybe an hour in the reloading room every couple of days. If I wasn't in there, I'd be watching TV, sleeping, spending money, etc.
Knowledge - not sure what you mean by this, but if you mean I'm not studying for my BAR exam or next degree, you're right - I'm not. I've a few years before retirement - professional growth is NOT a real problem for me. I do gain knowledge of my firearms and what they like to shoot with every handload rolled, for instance, yesterday to my chagrin my Uberti 3.5" Cattleman II Birdshead likes XTPs over my hand cast LRN or SWC bullets. Bummer, but good to know so I move my data search in another direction.
Wear and tear - on what, me? WAY too late for that! Between the military and 22 years of working in prisons, I think I'm dang near worn out already. However, the physical parts of reloading are VERY slight, to be honest, most is done sitting down!
On the equipment? Been using the same single stage press for almost 20 years, and it was built in 1982. I think I can safely amortize it down to zero. Even my 6 cavity Lee mold that I finally retired gave me THOUSANDS of bullets before it gave up the ghost. Wear and tear on the gun? Is it not there to be shot? If you just like safe queens and wall hangers, hey, that's cool, saves you every single dollar on ammo possible by never shooting a single round. I know a person with a commemorative Colt SAA that has never been fired and never will - it will be perfectly preserved for when she dies and the next family member inherits it.
You don't need reasons to not reload, if it's not for you, that's totally cool, saves components for me and my kind. No worries whatsoever, but no need to make stuff up, man. Just say it's not your bag and leave it at that, we understand completely. For instance, I know every step on how to change the oil in my car - I will always pay someone else to do that, because crawling around under a car "ain't my bag, man. "