I detest 'we was' and 'I done' with a passion, but I do accept that it is a regional thing and I've had to learn to live with it or I would have spontaneously combusted long ago; having always lived in Kent or Essex I am surrounded by the English-mangling fuckers.
It's still WC sloppy bad grammar thing though, plain and simple.
Ironically I notice that people from Yorks and Lancs often say 'I were' which is the grammatical opposite of the mistake 'We was.'
Why can't people just say it one way - the right way? 