No logic here ... simply what I experience. In daylight I have to search for that little red dot. That takes time. During this time I am focusede on seeking that little red dot, not the target (personally in bright California sunlight I find it very hard to see).
After practice, using the CT grips, I change to regular grips for my J-Frame. The 340 CT has the tritium XS front sight. In a bad encounter I hardly am thinking in terms of bullseye sight alignment. A quick target acquisition is in my opinion what is in order. Since 7 yards and less is pretty much the range I am concerned with, I am content to use the large XS white circle as my sight and it is quick to focus on target ... close enough for inside 7 yards anyway.
Simply put, no logic, I personally find it quicker to 'Point shoot' with the J-Frame inside 7 yards, rather that take time trying to find that little red dot. The little red dot is not my target and I see no purpose in giving any time, or energy to it in what may be a very serious situation.
Different strokes for different folks.