I don't think people have not read those verses.
2 points come to my mind.
one....women do all sort of things , to stay beautiful . May be , Covering their head is an effort to conceal their poor hair .May be they think covering head gives them an another dimension in beautifulness. They can't do that in public as this is considered as inauspicious.
They never mind bible teachings , if it come across their life style . eg. they put aside the following verse when they want to wear Jeans.
உபாகமம் 22 : 5 புருஷரின் உடைகளை ஸ்திரீகள் தரிக்கலாகாது, ஸ்திரீகளின் உடைகளைப் புருஷர் தரிக்கலாகாது, அப்படிச் செய்கிறவர்கள் எல்லாரும் உன் தேவனாகிய கர்த்தருக்கு அருவருப்பானவர்கள்.
two....it may be derived from the old Palestinian culture .