In my twenty-five years of working as an editor, no style issue even comes close to being as contentious among editorial staff as how to treat bulleted lists. This is one of those areas where there is no right or wrong answer; it's just a matter of deciding how to do it, and then ensuring that it is done consistently.
Solo editors don't have to grapple with this; each can unilaterally decide for himself. The problem arises when a group of editors—responsible for style consistency across an entire product line—tries to reach consensus on this question.
The possibilities are as varied as the opinions of editors on this question: initial cap or not? closing punctuation or not for each item? closing punctuation only if a sentence? And so forth ad nauseum.
I had a job where this issue was debated at every editorial staff meeting for a year! Honestly. At the risk of being sanctioned, or worse, I finally announced that I would no longer remain in meetings that rehashed this issue. Before I left, I proposed (again) the only viable solution that I had seen in my experience, one that all editors could remember and didn't involve exceptions to the rule or any decision making: every bulleted item starts with a capital letter and has no closing punctuation mark. And I repeated my plea to the editorial manager: Just make an executive decision on this and establish a rule. He never did, and I wouldn't be surprised if that discussion is on this week's meeting agenda.
What gives life to endless discussions as the above (aside from poor management), are two off-putting traits of many editors: the belief that they are always right, and the love of discussing the esoterica of editing. But that's a story for another day.