There is a huge difference between lagging indicators and coin tosses. If you're putting money on the line, you should understand the rationale for your trading decisions. Otherwise you might be a victim of spurious correlation (e.g., trading based on moon cycles or some other nonsense that just happens to work out sometimes), or you may not understand the risk (picking up nickels in front of a steamroller, to use an analogy I'm sure you're familiar with).
There is also an argument to be made for capital efficiency. So if you used the back of an axe to hammer nails when you had a proper hammer available, there is room for improvement.
This was not a meaningless argument. It was a good discussion (with a few exceptions that you'll find in most threads).