Nothing is guaranteed even if you travel before the expiry you can still get denied. Each application is reviewed on it's own merit at the time of interview however previous travel and return without violating the visa status does help but does not guarantee approval.
As much as people like to say it's the mood of the consul the fact is it's not. They still have to follow regulations and you as the applicant must show proof that you have no intention to reside in the US. Each denial must indicate the reason for denial within the bounds of the law with the section of law indicated. Keep in mind that the law also presumes that every applicant is an intending immigrant unil the applicant can show otherwise. The same goes when you arrive in the US and meet the officer at the airport, the visa is not a guarantee of entry into the US. It is only a form allowing the airline to board the person bound for the US without getting fined, the officer at the airport of entry will decide if you are going to be permitted to enter or be sent home.
Code of Federal regulations for the State Department
http://www.uscis.gov/propub/ProPubVA...b1c58f5df66d79
These are the laws used in approving and denying a visa. Most denials are under this law.
Sec. 40.6 Basis for refusal.
A visa can be refused only upon a ground specifically set out in the law or implementing regulations. The term "reason to believe", as used in INA 221(g) , shall be considered to require a determination based upon facts or circumstances which would lead a reasonable person to conclude that the applicant is ineligible to receive a visa as provided in the INA and as implemented by the regulations. Consideration shall be given to any evidence submitted indicating that the ground for a prior refusal of a visa may no longer exist. The burden of proof is upon the applicant to establish eligibility to receive a visa under INA 212 or any other provision of law or regulation.
Do you know for sure the person was denied because of the mood of the consul? Unless you do then you can't say it's the mood of the consul. Remember they now take fingerprints then check if you've violated any laws in the US while you were here.
But it is true that the Philippines is always in the top 5 for illegals and at one point was number 2 to only Mexico.