If it were pure and simple racism, then they would not mimic the accent of their own kind, the provincial Tagalogs but they do. Batanguenos have more of their share of this "abuse" than their Bisayan kababayan. Batanguenos, however, don’t get offended and indeed, when sensing that their Manileño cousins make fun of their accents, they all the more showcase their delectable solid Batangueño accent!
The thought that perpetrators of this form of linguistic “racism” are always Tagalogs themselves is in itself nearer to the essence of racism by lumping all Tagalog people as insensitive idiots with a bloated superiority complex.
Truth to tell, this tendency to mimic other people’s accent is shared more or less equally by many Manileños whether they themselves are actually Ilokanos, Kapampangan, Bikolanos etc. Cebuanos are equally guilty of laughing at non-Bisyas who err when speaking Binisaya. So instead of blaming one linguistic group of people for this crime, let's just blame human nature.
Some of the more hilarious Tagalog variations are not those spoken by Bisayas or Batanguenos but by Americans, Chinese and Japanese. (I once heard the Russian ambassador in Manila spoke in Tagalog, and it was so close to Manila accent that it almost felt frightening).
My wife laughs at me a lot whenever I try to speak or write in Bikol, her native tongue. She's usually amused or flattered but yes, I sometimes detect a faint sense of pride or even superiority on her part but it is no way near that ugly word, racism.
I myself always get caught in perpetual awe upon hearing the Illongo language. I don't understand it nor have a desire to learn it anywhere in the near future, but I consider it music to my ear. Some of my Ilonggo friends may have sometimes get offended when I try to mimic the way they speak Tagalog, but what they don't realize was that I secretly lust after their mother tongue.
Yes, Manileños need a lot of growing up to do when it comes to being sensitive with their fellow Filipinos, especially towards non-Tagalogs. This, however, is a case of immaturity or at least insensitivity, not racism.
----------If I could have my way, I'd prefer that Manileño kids be obliged to have at least a working knowledge of all the 12 major languages of the Philippines, and perhaps proficiency in at least 2 other languages (namely Ilokano and Cebuano) aside from Tagalog-Filipino and English.
What do you think?