In discussion we often find people only focusing on what they feel or think is "negative" of any religion or spiritual teaching.
Why is it so? Why do this people see all the good spiritual teaching add to someones life?
Mostly all spiritual/religioues people focus on the good of the teaching they follow, and if there is something negative, they try to understand why the teaching say so. Instead of getting mad or angry at a God or Buddha like those who do not understand spiritual teaching can do.
Why the negativity?
A lot of people are negative about their former religion because they've had personal experiences-both good and bad-and external factors may have influenced their spiritual growth and/or they realize they don't want to put time and their life into the experiences they have or have had. Instead of seeing it as a lack of experience and that's why they are negative, see it more, they have the experience but because of internal and/or external factors (both positive-lessons learned from or negative-people's influences), they decide not to follow that said religion or religious leader or authority.
A lot of religious people see the positive and the negative they see is through cognitive bias. For example, they may read that god punishes people for X and justify it as god's laws (they can't question his edict). While at the same time, they feel the need to help others despite the cognitive discordance that god chose otherwise. Some people cannot handle that cognitive discordance at the expense of having positive experiences. It becomes contradictory and that fight between experience and contradiction (by the person experiencing it) leads that X person to the decision-stay or go. Many ministers have left their religion because they found what's best for their spiritual well-being.
Many atheists have become religious because they had an experience that brought them to that faith that overcame the rational they would have had without that experience. Take people who have near death experiences and saw who they interpret as god. People follow god for these big experiences and they may or may not have heard and believed god to begin with. So, it's not because of lack of experiences. It's probably rare that there are atheists who have not had spiritual experiences but many do just not with a deity or deities.