Yes, people can and will sue for any reason. But in this case this is how the suit would likely go ...
plaintiff: "Your honor these share holders are suing the company for violating its fiduciary duty."
company; "Your honor, we know that some share holders may not always agree with the majority, but we made sure that over 50% of the share holders were on board with every decision we've made. We move to dismiss."
Judge: "You have documented that the majority agreed?"
company: "Yes your honor"
Judge: "And every shareholder has access to the bylaws of the company which state in clear and unequivocal terms that all decisions will be decided by a simple majority vote?"
company: "Yes your honor."
"case dismissed."
