@Lucien,
You have been a member of KKF for less than a month - so you deserve leniency
The Shigefusa/Kato question is a horse that has been flogged into its atomic constituents. To that extent, it is an irritating question for the forum to keep revisiting. In general KKF is a good willed place and the members are open and willing to share. You will find that people joke around in threads like this because it is hard to generate any new insights to a vague and well travelled question. Worse, they can descend into a pissing match about which colour is the best.... You may as well say green is 'overrated' and red is objectively 'better' (see the active thread
TF Wabi-Sabi, also started by a new member)
Do some searching/reading and you will find plenty of information about both blacksmiths. If you have some very specific questions remaining, you might get more active and useful responses.
Knives are tools. When you spend more than a certain amount and 'get into the hobby' they also represent a
craft. Shigefusa and Kato have long been regarded as fine examples of traditional handmade Japanese knives. They are valued as artisans, not just tool makers.
You are free to make your own judgements