Okay, I understand your complaints, but with every other event game mode put in place, certain champs are going to have advantages and disadvantages.
I'm going to guess that you don't like how you can't utilize champions such as Syndra and Braum - based off the strong references to them - as well in this game mode compared to the other normal games or previous game modes. Though, there is still flexibility with these two champions. For example, since you start out at level 3, you can reach your passive much faster than in a normal game with syndra - however since it's a very assassin heavy game mode you will of course suffer from her natural lacking of defenses. As for Braum, as long as you don't have a team comp of mages or AD casters, your passive and kit really helps go against said assassins and protect relics while being captured.
Also, Xerath being weak is almost what makes this mode so fun for most people from what I've heard - and my own personal experiences of course. It makes it so that it's almost a race to see who can get him without it being stolen and it's a high priority objective that everyone wants to have. It's easy power that makes for a fun hunting dynamic since the ascended champion cannot be hidden on the map. And people that are demoralized simply by losing one Xerath kill are playing this mode for all the wrong reasons (( IN MY OPINION OF COURSE!! )) because the game shouldn't focus on getting the prize, but having fun with a new and interesting mechanic that has some special prizes if you meet certain standards.
Of course, there is always the fact that you may not like this game mode. This one just may not be for you and that's okay! Just hope that the next time around you'll enjoy it more than this one. :3