You are comparing uncomparable. You mention Spain and United Kingdom but LOOK AT THE LANGUAGES!!!! In Spain it is Catalan, Basque and so on. In UK it is Irish, Scotish, Welsh, and so on. That languages are PART OF SPAIN AND UK). It is the same like if you would put as an official language in Czech Republic i.e. Moravian language (and that´s OK!!!). Realize that in almost every country in the world there are (some legal) exceptions when it is possible to use other than the MAIN language (but is absurd to put it in the main infobox on Wiki to confuse people (they come to Czech article on Wiki and they see that official language of CR is Russian!!!?)
 Regarding the Wikipedia definition of official langue - that article is editable as anything on Wiki - so please dont link to Wiki (as a source).