While it's a good reminder, you may be taking things a little far. If I recognize that spot correctly, it is only deep for 10-15 feet along the backside and then shallows and slows out considerably.
Some people are more confident in their wading skills, and have stronger legs, better balance, more weight, etc. What you may perceive as dangerous or stupid may be a cake walk to another angler. For example, you noted the knee deep side channel scaring you. That is your wading ability, while your buddy did that with ease.
The best advice I have is wade to your ability. The more you wade, the more confident you get, and soon you'll be "the idiot." I quite often wade waist deep fairly fast water, and I act as the water break and stabilizer for my friends that are with me. They would never do it on their own, because they don't have as much experience and aren't as confident. Likewise, one of my buddies does crazy wades that I would never attempt on my own, but having him help as we cross is enough to get me to the other side.
Last point I'll make is always look downriver. I'm much more willing to do a "risky" wade if it's smoother sailing below. Log jams, rapids, waterfalls, etc below will significantly impact what risk I'm willing to take.