Probably because some have the mentality some Mexicans do in with regards as to whether their a REAL Filipino or not.
And there is a logical reason behind this "Real Filipino" thing...
Filipinos here in the Philippines don't actually like fellow Filipinos who they deem as whitewashed or too Americanized, If a person claims to be "Pilipino" then Filipinos here expect to see them act accordingly as a Filipino, they expect you to possess the same values that all Filipinos have or give importance to things that most Filipinos cherish, here are some examples:
Filipinos see the Family as one of the most important, Religion or god also is important to Filipinos wether you're a christian or a muslim Filipino, respect to elders, Kahihiyan/Delicadeza, Smooth Interpersonal Relations (non-confrontational solving of disputes with in Filipino community) look this up, this is the exact opposite of "confrontations" in western culture... Donaire's being too "madaldal" or saying whatever is on top of his mind, (which is typical of American culture by the way), does not help either, because of this tendencies... he is often seen as "mayabang" or braggart.
It's easy as this:
If you act like a Filipino, talk like a Filipino, look like a Filipino, your values are Filipino, then most probably... you're a Filipino; the same also goes with... If you act like American, talk like American, look like an American, your values are American/western, then most likely you're an American. (take note: values play an important role on this one)
Filipino athletes who enjoy the greatest support from the Filipino people, are the ones who choose to represent the Filipino people the best, with the use of their extraordinary skills and showcase of Filipino values, like Efren Reyes of billiards (really humble and nice guy but very talented in billiards, all billiard champions all over the world adore and idolize Efren, an ATG), Manny Pacquiao (humble and kind person, god fearing person but also very talented in boxing, a future ATG), Gabriel Flash Elorde (Nice and humble guy, hall of fame in boxing); I also have to mention that, this people choose to represent the Philippines and Filipino people even though they are offered a citizenship and probably a better life by the USA, this great Filipinos chose to decline the offer and represent their people instead, no matter what... I can't say the same with Nonito and Viloria though, when they were given the chance to represent a country in the olympics, they choose to represent the USA, but now that Pacquiao has uplifted the Pilipino trademark in the world of boxing, Nonito and Viloria suddenly wave and carry the Philippine flag... this is the same problem which Oscar Dela Hoya encountered with the Mexican people aside from his bout with JCC.
Case in point:
You're a Filipino through thick and thin, there is no in between; you can't claim to be Filipino when it's just convenient for you. (take note: Pilipinos always remember/ keep tabs regarding this things).
It is also a question of "Where does your loyalty lie?"
As we all know, the Philippines have our fair share of wars in the past just like it's neighbors in Asia, and because of this Filipinos here in the Philippines, often ask or think... If ever we get attacked/invaded by a larger country, for example China or America, Filipinos here ask themselves... "Will this Fil-Ams who claim to be Filipinos now while we're on top, will this same Fil-Ams go back to the Philippines to help out or fight with us side by side? or will they just deny and ignore the plight of their own people and claim only to be Filipino when it's convenient for them? Will they sacrifice their comfortable life abroad just to be in a wartorn land and defend the Philippines?"
This is a real question and dilemma which is not unique to Filipinos and is also asked by other nationalities among themselves, when USA attacked Afghanistan and to some point borders of Pakistan, young Pakistanis who grew up in the U.K. are the ones going back to Afghanistan to become freedom fighters or suicide bombers, the point here is... their motherland (Afghanistan/Pakistan) needs them and they willingly heed the call of their mother as good sons and daughters.
During WW2, Pilipino farmers in USA, went back here to the Philippines to fight the invading Japanese Army... this old Pilipino veterans are real sons/daughters of the Philippines, their mother is in distress and they go back to help her.
Case in point:
Fil-foreign/Fil-Ams have Filipino blood flowing in them, and therefore are considered as Philippines sons/daughters, considered as Filipinos, but... the real test of knowing who the "true"
sons/daughters of their motherland is... when your mother (Philippines)
is in danger and is calling out for your help, her only children that come for her aid are the only ones to be considered as her "true"
sons and daughters... "True"
There is also the hypothetical question of:"If Philippines and USA go to war against each other, who will the Fil-Ams fight for?
This is an intriguing question asked by American expats living here in the Philippines, most of them love their life here in the Philippines, most choose to stay, but you'll be surprised with the answers in this discussions, on the comments section... the founder of the site is a friendly expat, with a Filipina wife and kids, he also loves the Philippines so much, so please refrain from leaving unsavory comments in his site.Link here: http://liveinthephilippines.com/content/2010/01/where-do-your-loyalties-lie/
This post does not intend to ostracize Fil-Ams/Fil-foreign but instead, this are just few of the insights I can think of, to answer the title of the thread... this are actually thoughts to ponder... I still believe that, as long as we're united we are strong.