I didn't say anything close to that.
I don't think so. Everything that wort touches gets dirty with organic soil and beer stone and it builds up every time you brew.
I'll try some different ways to explain it.
Most people would argue that the best justification for using TC ports and accessories on brewing equipment is the fact that the liquid flowing through them is only touching very smooth surfaces with very few nook and crannies for soil to build in. Additionally, because all the TC connections are held together with a single wing nut actuated clamp, that taking everything apart for an even more thorough cleaning is possible and practical.
I grant that as all true. Where that argument crumbles is when some of the TC connections are not native, such as when the ports in the kettle are threaded or when the valves are threaded, etc. In that case, threaded to TC adapters are somewhat the worst of both worlds. The NPT side of the connection is practically as hard to clean as a system with ALL NPT connections and the TC side has all the cons I mentioned (bulk, cost, cumbersome).
1. The inherent nature of exposed threads to collect soil over time and the fact that most people would be reluctant to break all the threaded connections down on a regular basis. Threaded connections are perfectly fine on the hot side, in my opinion, for many batches without a full break down IF a rigid clean in place process is followed after every brew day. Hot PBW circulated through all wort paths for 30 minutes with a thorough rinse and as much physical scrubbing as a couple brushes can reach.
2. Ball valves present a special case related to cleaning in place. That is the fact that ball valves have a pocket behind the ball, in between the seats, that is completely isolated from the flow path when in the full open position. While brewing, the operation of the valve open/closed/open will let wort into that pocket. When you're doing a circulatory cleaning through that valve, you have to leave the valve half way open to flush that area out. Not doing this usually results in people eventually taking the valves apart and being horrified at what they find in there. That usually causes that person to vow never to use ball valves again and that TC/butterfly valves are the only way to go. They would be misinformed in my opinion.