If a log works for some people by all means use one, I don't think it makes one a better fisherman. A good fisherman is able to adapt on the spot.
So many factors involved that can affect the conditions day to day and certainly year to year. Luckily where I fish for bass my main concern is water depth, vegetation and cold fronts, all I have to do is walk over to the canal or pond to visually see what's going on. Not only does the weather control water depth it's also controlled by man, gates are opened and closed based on rain as well as getting ready for a big storm. We have sea lettuce down here, today a canal can be totally clean and tomorrow that lettuce is thick making fishing very difficult.
Many people fish for multiple species, quite often those fish come into areas certain times of the year. Those fish follow bait, bait is controlled by water temperature and weather, bad storms bring snapper in for example. I've had years where I've caught bluefish left and right, the following year hardly any, the water and weather isn't the same. I've seen fish delayed as much as 2 months behind their anticipated schedule. Huge difference between a wave and a groundswell, there is no consistency. A good fisherman knows their species and the nuances of each, don't find too much difficulty in being able to keep that info in my personal computer, that being my head. A log is just a guideline, which is not always accurate.
Not everyone experiences this scenario which happens all the time here. I've caught some really nice fish, just taking the time to take quick a photo can cost me a cast to catch another 15 or 20# fish.