Producing such leaflets and communications duplicates costs and is a waste of money particularly at a time when serious cutbacks are needed.
It also discourages those living in the UK who do not speak English from learning the language. Why bother when everything you need is provided in your own language and translaters are often provided for all sorts of 'needs' from dealing with councils to hospital visits, school meetings etc. If non English speakers were encouraged to (not paid to!) learn English it would lead to a more integrated society too.