My reaction was similar to timster's. Asiana is a good program for someone who flies on moderate priced fares, but you could easily find that you'll earn zero or 25% on the cheapest economy fares. Seoul and Shanghai are also short flights, to where even earning at 100% doesn't get you much.

Ideally you should have some more insight on which fares exactly you can fly on. OZ offers their lowest fare class on the TYO-SEL flights right up until the last minute on many dates which earns a blanket Zero miles in all *A programs (might credit minimally to OZ's own but think even there its a zero). You're going to find similar problems with TG or SQ going to SE Asia or Australia, their lower priced fares also earn zero outside of their own programs (and even I think TG is a zero in their own).

I'm not sure why people told you that Skyteam is bad for Asia. MU and CZ have great award availability and good networks, KE and CI are high quality carriers, plus you have VN for SE Asia and Australia that's quite decent. Flying Blue might not be your ideal program though as I think they have discounted credit for many partners on lower fare classes, you might find yourself better off looking at DL Skymiles for Skyteam. You'd get 100% MQM credit for MU and AF flights, and then others depend on fare class. There are some zero earning fares on KE, CZ, and VN for sure, not sure on CI. Flying Blue is also not much better for redemptions from Japan than DL Skymiles. FB is great for intra-Asia awards in the southern region, but Japan & Korea are in a different region and it gets a lot more expensive for intra-Asia awards from there, nearer to the same as Skymiles.