Not true, many better things for blue defense than ritual flames at this point and who is to say which boost higher levels of GE will need.
Check again. Here's a short list of buildings that are better (i.e. more efficient) than an L2 Ritual Flame for blue defense:
1) Tourney Grounds (difficult to sustain w/o lots of GBG battles)
2) Tower of Champions (only available to top Diamond Guilds)
3) Royal Tower of Champions (only available to top Diamond Guilds)
4) Hydra (difficult to build for all but SAT players)
5) Royal Bathhouse
6) Pegasus (difficult to build for all but SAT players)
7) Observatory
8) Forgotten Temple (only available to players that complete GE80)
I may have missed something but there are not many things that are better than Ritual Flames.