I don't agree that there has to be a trade off.. Or see anything wrong with being patriotic? Surely valuing your own nation and culture allows you to appreciate other cultures better.
http://en.wikipedia.org/wiki/Patriotism
"Patriotism denotes positive and supportive attitudes to a 'fatherland' (
Latin patria <
Greek patrida, πατρίδα), by individuals and groups. The 'fatherland' (or 'motherland') can be a region or a city, but patriotism usually applies to a
nation and/or a
nation-state. Patriotism covers such attitudes as:
pride in its achievements and culture, the
desire to preserve its character and
the basis of the culture, and identification with other members of the nation."
Sure, Irish is not necessary. It may/may not be useful, but that will be a matter for the child when he/she grows up. If they end up speaking it regurlarly with their friends, take a sense of pride in it, or end up working in a job that requires Irish, then that will make it useful for them. If they don't ever use it again (unlikely) then at least being bilingual will give them the confidence of being able to master a further language. By sending them to a Gaelscoil they will become fluent Irish speakers unlike most of those that come out of the English medium schools.
I currently live in Switzerland (Zurich) where learning and speaking different languages is second nature. Here people speak and take pride in their local dialect, and learn German when they start school as a foreign language. The Swiss I work with generally speak at least 3 languages fluently. One girl grew up in a bi-lingual Romansch / Swiss German community, learnt German at school, is fluent in French and English, speaks a bit of Italian, and is learning Spanish. Only started learning English a couple of years ago, but speaks with almost perfect grammar, despite not having lived in an English speaking country.
We're fortunate in many ways that English is the main language of Ireland, but by virtue of it being the de-facto international language but there is one disadvantage: We don't have the same urgency to learn other languages, so generally we don't. Being an island doesn't help either.
Having Irish gave me the confidence to learn fluent Spanish in a couple of years, and I'm now learning German.