Good entries based on guesswork often go wrong because they are merely lucky or unlucky. Good entries based on scientific analysis (a very rare phenomenon in the trading world) rarely go wrong. Most trading entries are based on iffy patterns, iffy bar analysis and iffy indicators. Very little of it stands up to scientific scrutiny, hence the unfamiliarity among traders of what a science-based entry can accomplish.
I agree with you on most of above completely, most traders might aswell trade of tea leaf patterns for all the value that's in there methods, but still I'm yet to find an entry that is near enough 100% for me to leave it, don't get me wrong, my entries are GOOD, 74% win rate currently but still not buying it.
All the best logic in the world, doesn't protect against a random news events, like the Ukraine events causing 250pip down moves in the DAX in a previous uptrend. And 1's to smaller degrees ofcourse!