My experience with Fender P-basses has show me that USA, Japan and Mexico all produce good and bad basses. When I was younger I spent a lot of money to get an American P-bass, and I thought it had to be the best quality bass there was. One night I was at a buddy's place and was jamming on a jazz, it felt fantastic and sounded great, which made me believe it was definitely an American. When I checked, to my surprise it was Mexican. I started experimenting with different countries afterwards and noticed that testing out products is more important then relying on their country of origin.
In an ideal world (as opposed to the world most of us actually live in), country of manufacturing origin shouldn't matter in terms of quality, but can often be an indicator of what to expect in terms of materials, features and attention to detail. Which to many of us, equals "quality". Is it important or worth paying extra for? You decide.
To wit; Cort, a large guitar manufacturer presently located in Indonesia, builds guitars for many different companies according to said companys' specifications. Cort and some Korean makers have the capacity, skills, and access to resources to build everything from cheap entry level guitars to sophisticated high end guitars. It all depends on what their clients are willing to pay for. Many companies reserve the building of their "premium" line of instruments to be made in their home countries, while still being able to offer more affordable guitars by employing off-shore factories.
The trade off is usually (but not always) lower grade hardware, electronics, fewer options, and in some cases a lower grade of woods. Most guitar manufacturers from giants like Fender, to smaller production outfits like G&L, EBMM, to high end builders like Sadowsky, Brubaker, Lakland and others, use the same strategy. Namely, a lower priced import line, similar to their premier offerings, but with some quality or feature trade offs.
Does this mean that an Indonesian-made Lakland Skyline or a Mexican-made Fender are not perfectly serviceable guitars? Of course not. Does it mean the same quality level of parts and materials are found on both versions? No. Why would it? It's just how The System works.
OTOH, there are ways to "beat the system" if you know your gear, and know exactly what your preferences are. Yes, there are sleeper deals out there just waiting to be discovered. Cheers.