The trouble with Kabalah. The constant craving for spiritual experience,as is attested to by all the great mystics,is addictive, like a drug. If the experiences are indeed spurious,they will never ultimately satisfy the soul that hungers after them, and will be required in stronger and stronger doses.
But Kabalah became embedded in Musar from the start. It is an inevitable step from traditional Musar into Kabalah and from their into worlds of delusions of grandeur.
Not that this was the case with authentic mystics like the Ari or Bava Sali.
You can see why Reb Chaim and Brisk did not have Musar as part of the daily session. Kabalah tends to lead to a kind of world view in which the experience and high LSD high gives validity to what ever the ideas are.
There is a problem with the slippery slope.People can not change the Torah openly because no one would accept that. Instead they claim mystic visions and explain the Torah in the way they want. That way they think they can nullify the Torah and be accepted.
Once the pursuit of spiritual power replaces the striving after straight Torah, then the flood gates have been opened up and it is only a matter of time before there will be an overwhelming confusion of spirits,and error and division will be the order of the day. The world of the religious today is sadlly overwhelming from the Dark Side Sitra Achra. That is not do there there is no spirit at work there. However it is not the spirit of God but rather the occult.