So when you repotted your phals into better ventilated pots, did you change the media as well? If so, your plant may just be going through a transition period. Sometimes they sulk when repotted, even if it's what's best for them. The spike may be dying because now the plant is using its energy to grow new roots.
Also, I am having trouble telling from the picture: do the lower leaves look worse than the upper leaves? Sometimes if the plant can't support all of its leaves, the lower ones start to die.
Also, what did you repot it in? Sometimes new medium (especially bark) dries out faster than older medium, so you may just need to water more for the next few weeks until the mix opens up