For those of us who live in the United States, this is a question of nearly-endless debate. There are those who believe American-made guitars are always better; and, conversely, that guitars made in China are invariably inferior. Others believe one should choose a guitar based on sound and price alone, ignoring where it's made. Some folks are virtually married to a particular manufacturer and wouldn't consider buying anything else. To still others it's an ideological thing; they typically think either a) that buying American shows one's patriotism and should be invariable, or b) that buying products from emerging markets helps the world's poor. My view doesn't fit neatly into any of these categories, and yours may not, either - but as a general outline of the arguments for and against, this seems to suffice.
I buy a lot of things made outside my country's borders, sometimes by choice but most of the time because there is no choice. As an example of the former, I like wine, and in addition to California and Washington State wines, I'm partial to those from Australia, Spain, and Italy (most French wines just don't do it for me). On the other hand, when we buy clothes in the United States today there really is no choice - I don't think there is a single textile plant left in the US, and the vast majority of our clothing (other than, perhaps, the uber-expensive kind) comes from elsewhere. I read recently about a guy who started a company to produce high-end men's shoes, and planned to manufacture in the United States - but found out the hard way that there is no one left here who can service the complex machines required for shoe making. I would say that the majority of what we buy in the US today is manufactured somewhere else. Even the old bastion - American cars - are made from parts produced all over the world, with final assembly often in Canada or Mexico. I recently chose a Toyota, because it was at least assembled in a plant in Kentucky that employs American workers
With all that as a backdrop, guitars are the exception in today's world. The United States probably produces more guitars than any other country, and the best guitars in the world are produced here. That's not to say that every guitar made in America is automatically better than every guitar made anywhere else. Still, I don't think there is any comparison between the best guitars produced here and the best produced anywhere else. Just think of the incredible guitars made in the US by Martin, Gibson, Fender, Taylor, Guild, Collings, and Santa Cruz, to name just a few - not to mention the countless independent luthiers out there making custom instruments. Some of these companies (most notably Martin, Gibson, and Fender) make the standards by which all other guitars are judged.
In most cases I don't have the option to buy products made in my home country, so guitars are kind of my line in the sand. I have a strong preference for American-made guitars - which is not to say that I would never buy a guitar made outside the US. After I've collected everything on my wish list (which is, admittedly, probably too long to get through in my lifetime), Takamine makes fine guitars, the Epiphone Masterbilt series is pretty good too, and I'd like to have a Taylor GS Mini, which is made in Mexico. And this is a personal decision - I harbor no ill will for those whose preferences lead them in other directions.
On the other hand, I'm not fond of hypocrites. For example, Toby Keith makes a show of being pro-American (worker, soldier, etc).; but he plays Takamine guitars. I saw a televised stage performance of his recently, and he was playing a Takamine with a top painted like an American flag. Toby, if you prefer Takamine that's fine with me - but don't then try to convince me of your solidarity with the American worker, when there are outstanding American made guitars available and you have the money to buy any guitar you want. Glenn Frey plays Takamines too, and I have absolutely no problem with that because the hypocrisy is missing.
So, my bottom line is, buy whatever you like, and I'll do the same - but don't try to have it both ways like Mr. Keith. I prefer American-made guitars, but that doesn't mean you have to. At the end of the discussion, the point is to make music and have fun doing it.