Those are design decisions of developers who see the game more group placed.
In factions a blue cannot unhide a normal blue factioner now which they could before - is actually my guess why they changed it.
Also a big advanatge is that your own friends if blue don't unhide you now.
These are all changes which creep in since they removed 'friendly fire' which is normal in popular games, though why UO makes these changes I don't know, as they don't really make the game better.
I doubt they considered the repercussions these changes have on other playstyles too much.
It is not as if I disagree with you here. It is not even as if I do not try to empathize with the dev team, I also am first in line to compliment them on any kind of forward thinking, or putting themselves out there...But some things should be consulted.
I am not against balance, I am not against change, I also am not against "almost" forced group play. But this change did none of it...The only thing in mind that might work as an excuse is as you said, factions members can reveal same faction members. While that at least makes sense....Who complained about it? More so, why not just make it like the other "same faction screw up" where it don't work against same factions, same guild, allies, and the such? I mean...if they can make my pet ignore same faction people, even if they go grey against me, why not be able to do that?
I don't mind many of the intentional changes to the game, aside from this one the only other intentional one is the potion weight, while I do not pot...it just does not solve the problem. But at least with the potion weight they went ahead and explained themselves, despite their logic being...off. I just wish there was some kind of reasoning behind some of these intentional changes.