The big deal is things like access to DLC and other transactions you've made. Bloodborne, for instance, is tied to my HK account, an account I can no longer access. Over the years, after using an American, Canadian, Taiwan and HK account to buy DLC for games (living in China, you get physical copies from various countries at stores), I was signed out of my HK account (Why? I don't know), and when I tried to sign back in, my password didn't work. Unfortunately, it being so long since signing up for the account, I forgot what email I created and registered for it. So now, all of the DLC for the HK games I bought, is lost. I was also signed out of my US account, but managed to figure out the email tied to it, and change the password, so I had access to it again.
Could I have managed my accounts, and all of the information tied to them better? Sure, and it's something I certainly do now, but it still sucks to have to do this in the first place. Why do things like DLC need to be region-locked? Why can't I buy it through my Canadian account for my Korean/HK/American/Taiwanese physical discs?
All this does is make me spend less.