Let's zoom in to the two languages of English and Mandarin. I
come from an English-speaking family. Both sides of my family
speaks english. But i can speak mandarin pretty well too, although
there is an English accent in my speech.
I see no disgrace in being a chinese who doesn't know how to speak
mandarin. There are lots of whites in the States whose English
isn't that good either. Some can't even spell as well as us.
Well, to me - Chinese is just a tool. You can't deny that English
is - THE INTERNATIONAL LANGUAGE. It is the MAIN gateway to
communication. Chinese/mandarin will NEVER be an International
Language. Even the Chinese are starting to make it compulsory to
learn English, or at least a beneficial option.
The key to good communication is to allow yourself to be
understood. I've got people speaking f*cked up English as though
they come from China. F*ckin' terok. They got me f*ckin' fed up.
Thus, when I see them struggling to impress me with their
'excellent' English, I switch to Mandarin and Singlish.
Imagine that situation when they're speaking to a foreigner - your
usual Angmoh. If you're that Angmoh, would you like to have any
business deals with them? [A chicken talking to a duck] Well, the
same could be said for your Chinese counterpart. 
The European countries, the States, etc ('the angmoh markets') and
even India - how many really know how to communicate in Mandarin? I
know that the Chinese market is there to be tapped, but the quality
- be it labour, products and goods, services, etc ain't as
established, renowned & 'value for money.' Like they say - 'you
pay peanuts, you get monkeys.' 
Why do English-speaking people stereotype Chinese-speaking people
as low-class? Please take a look at your lovely Chinese Ah Bengs.
Do you wanna unconsciously wear their cheena tags? 
Oh, try flirting with an 'angmoh-pai' girl speaking in mandarin.
She'll give you one tight slap and ask you to f*ck back to China.

One way to rid the barrier is to be effectively versatile in
changing your way of speech according to situations. (ie. ability
to code-switch, which is an advantage.)
Unfortunately, most Singaporeans can't. But fret not, Singapore
loves cheenas, if you had noticed. Nobody cares if you're good in
English. 