Seriously? This post is enough to make one's head explode. You did read the thread right? It is for a high end build. Ryzen 1600 is an absurd choice for this. In fact the availability of Coffee Lake has moved the 1600 from a very viable *budget* gaming cpu to a very difficult processor to recommend, IMO. Even the i5 8400 is faster. Not to mention the availability of the 8700 and 8700k. In fact, a high end build screams for an 8700 or 8700k. The only possible advantage Ryzen has is the availability of 8 slower cores, which *might* make it relatively more competitive in streaming, but my choice would still be 8700 or 8700k, without a doubt. It will be a clearly superior gaming processor in everything but streaming, and with 6 fast cores with hyperthreading, I think streaming performance will be very good as well.
There will always be people recomending the 1600/1600X for the 'cheap but good enough' tag, it's a viable option for budget builds certainly, due to the cheaper price of the B350 motherboards. However, for a high end build I would agree with you, the i5 8400 makes it somewhat redundant as a gaming option unless streaming, and even then, I should point out that Gamers Nexus uses a very high bitrate (10Mbps IIRC) for their streaming benchmarks which is very CPU intensive and will obviously favour the higher threaded CPUs.
However, if using a 5Mbps bitrate for streaming, the CPU overhead is far less and even an i5 8400 can outperform a Ryzen 7: https://www.youtube.com/watch?v=agcwU1ImIqE (at 2:26 for DOTA and PUBG streaming benchmarks)
Of course, a 8700/8700K should be the default choice for a high end $1500 build, but you can get away with an i5 8400 which is fast enough to push any GPU except perhaps a 1080 Ti @ 1080P without bottlenecking.