Those whose karma is high quality (they have an aptitude to awaken) are far and few between. For the huge unfortunate majority their karma is not so good. Even if they went to the best teachers being immersed in their spiritual light thousands of times they would still miss it. We should not forget that the Buddha talked about these kinds of people. He called them pṛthagjana.
The pṛthagjana is the ordinary person—a worldling you could say. They have worldly aspirations—more so than spiritual aspirations. They have yet to attain the supermundane path of seeing, darśaṇa-mārga.
In the old days, where there might have been a teacher or two who had awakened to the One Mind; who was like a mini-sun radiating spiritual light, they dispensed the proper medicine to pṛthagjana in hopes that their karma would improve and they might lose their attraction for worldly ways and things.
Today, it is far worse. Only a few know of this light while many more are still in the bad habit of misreading Zen and Buddhism in general. According to Zen master Yuanwu these people, “are still wrapped up in making emotional interpretations and claim that there is no such thing as entry into enlightenment” (Cleary, Zen Letters, 48).
When I was much younger I met these people all the time in Zen centers and even Tibetan Buddhist centers. It was like they were suffering from a mysterious incurable disease. They were even impossible to reason with. When it came to Buddhism, they could read the translations but they had no idea what the translations were talking about. At times such people reminded me of the walking dead in the movies—not quite has hideous looking—but they were soulless.