I do believe you when you say you don't know anyone who speaks Gaelic, @SoMuchForSummerLove . But I wonder if you've heard people speaking it and not realised? Would you recognise it if you heard it? I'm from the Highlands, but have spent brief spells living in more than one Scottish city, and heard it many times; in shops/bus stops/on the street etc. I'm not saying it's prevalent, but to insinuate it isn't spoken except in the Highlands is a bit much.
I also don't think speaking Gaelic, or Scots, or Doric, makes you any more Scottish than someone who doesn't.
I think it would be great for all children in Scotland to learn a second language from very early on, as it's been proven that being bilingual is massively helpful to educational development. I can't see any argument against being smarter AND getting a free language which may (or may not) enhance your job prospects later. For that reason I intend to put my children through Gaelic medium, and would do so even if I had no Gaelic myself. If Gaelic wasn't available, I'd put them through French/German/Spanish medium, even if I thought they'd never use the language again. Like you, I don't agree with forcing it on people, but, given free choice, why wouldn't you give your kids this amazing kickstart?