I agree with you completely. But then all forms of national pride is irrational, if we really think about it. If everyone thought like TobyFaletauJones then Welsh would already be dead, and we would have lost an important part of what makes us who we are. This would be true of many other languages across the world that aren't really 'needed', Afrikaans for example. Looking further ahead, with English already recognised as being the the preferred worldwide language for doing business, politics etc., and likely to keep expanding, then more and more languages would die out with this kind of thinking.
Despite being terrible at languages (I'm fluent in English and Welsh, but languages were my weakest subjects at school, and I was terrible at German), I think much more emphasis should be put into languages in school (with new languages introduced aswell, such as computer languages), especially early on in primary schools where a childs capacity to learn a new language is at it's highest. I understand the problems with this (the lack of techers up to the required level in a second language), but an effort should be made. Music teachers travel amongst schools (I remember a violin teacher coming once a week to my primary school, despite it being in the middle of nowhere and only 25-30 pupils), surely a similar thing could be done with languages (and sports for that matter). Either that or primary school teachers should be required to know a second language, in the same way as they're expected to understand mathematics, sciences, history, geography etc. to an acceptable level.
A problem with this, however, is that language acquisition best takes place between the ages of 0-4, and while children can pick up language incredibly quickly at that age, it still takes four years to develop a reasonable competence. Teaching second languages in schools is always a struggle because, simply, it depends first and foremost on the individual's willing and ability to learn the new language.
The unfortunate reality for a minority language anywhere in the world is that the loss of native speakers leads to a loss of the 'soul' of the language. Compulsory learning of Welsh in schools does a lot of good for the profile and spread of the language, but it only has a slight effect on the general strength of the language. As I understand it, Irish is afforded a huge status in Ireland, to the extent where it is compulsory in schools, signs are bilingual, and they even translated their anthem into Irish. This has been the case for much of the 20th Century. Yet Irish, still, is dying, and that is because the native speakers in the Gaeltacht regions are dwindling. Far more people supposedly speak Irish than speak Gaidhlig, yet there are more native speakers of Gaidhlig. Personally I see Gaidhlig in a far stronger light, just because half of the Gaidhealtachd is in the Western Isles and those islands have such a strong connection with Gaidhlig. Ireland doesn't have the benefit of an insular Gaeltacht and so the native speakers of Irish have a much greater exposure to English.
One massive problem is native speakers moving away to a big city for uni/ work. They'll speak English there and potentially meet their future wife/ husband there, who most likely will only speak English. When they have kids, it's entirely up to the Welsh/ Irish/ Gaidhlig speaking parent to ensure the kid learns that language as a first language. Otherwise, they'll be in a similar position to the majority of Britain - in other words, a native speaker of English and nothing else.
Combatting this, you have schemes by governments etc. to halt the loss of Welsh/ Irish/ Gaidhlig. In Gaidhlig there was a direct translation of Tony Blair's 'Education, education, education' slogan - 'Foghlam, foghlam, foghlam', which refers to the need for Gaidhlig schools to be set up. Here, the language is used every day and so its 'soul' survives. Enforced learning of it as a second language, as is the case in Ireland, does nothing for this. I learnt French as a second language from 4-18, and am now fairly fluent. But still, I barely use it - even though I have three close friends who are native speakers of French, two who I see on a daily basis. Furthermore, I know a fair few idioms and metaphors, but I couldn't really be said to be able to speak 'colloquial' French. With minority languages the problem is greater - of four Gaidhlig teachers I've had, only one was a native speaker that grew up in the Gaidhealtachd. So I'm learning Gaidhlig that's been learnt. Not ideal.
Basically what I'm saying is that a language needs native speakers - and in the context of Welsh, that means that if you want the Welsh language to survive and thrive, you need to speak it at home with your kids from the second they are born, and hope that other Welsh speakers do the same.