well yes its possible to paint every picture just using the color red. but the existence of other colours....well they appeal to some artists.
if you lack the ability or imagination to use them, fair enough.

but its a bit like a cook who can only cook sausages , so when he cooks christmas pudding, it has to look like a sausage.

if that's what works for you, stick to it. but don't make rules for the rest of us. the idea that one has to sing a bach recicative, schuberts liede, elvis presley's all shook up and the galway shawl in ths same voice that was inflicted on you from birth doesn't make much sense to most people - or thankfully most singers.