English and other Latin languages were around at the time Gurbani was written. Our Gurus were well travelled and probably aware of them. Still they chose Gurmukhi was they found it was the best script to unify all the Baani under one Framework. Remember, Gurbani from other 'languages' were not chosen to support many languages. The primary reason was that they were spiritually relevant.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/general-discussion/38801-akhand-paath-languages-other-than-original.htmlReference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=38801
See this award winning documentary on Gurmukhi
http://www.sikhnet.com/video/35