Deep contemplative attainment does not make a person perfect; it confers mind power, a sense of happiness which is not dependent on circumstances, and a basically loving orientation toward one's environment. It does not, however, automatically guarantee immunity from stupidity, poor judgement or cultural myopia.
Furthermore, each meditative system has its characteristic weaknesses. Theravadan Vipassana meditation could make one humorless and depersonalized if not balanced with loving-kindness meditation. Tantric practice can easily degenerate into manipulation, sterile ritual and obscurantism. Belief in original enlightenment and just sitting could get in the way of rapid growth. In Japan, Zen training, particularly Rinzai training, can be brutal and imbue a tendency towards authoritarianism. In fact, Zen suffered a temporary eclipse in Japan following World War II precisely because it had been widely used as an underpinning for militarism. The practice of meditation to get tough and the cultivation of detached repose so that one may kill and be killed without fear or compunction represents a tragic perversion.
Finally, it is a mistake to identify meditation with a particular life style. Obviously, if one's daily life is seamy and chaotic, it will be difficult to attain a settled mind, but it is ludicrous to think that a person must be a vegetarian or enter a monastery to make headway in meditation. Such externals can help. They can also distract. The path to freedom is systematic and open to all. You don't need to be a Buddhist to profit from Buddhist meditation.
That these aberrations and misdirections exist should not in the least surprise, dismay or discourage us. Every tool can be misapplied. The fact is that each of the above approaches to meditation, if skillfully and persistently cultivated, produces a well-balanced, fulfilled individual whose very presence benefits his or her fellows. As such, they represent significant and powerful contributions to human culture.