Basics training is basics training, you don’t get to be a good pilot without getting the basics of attacking and defending hammered into your head. Ground attack training using unguided munitions is exactly that, getting the very basics straight. This isn’t about realistic scenarios, think doing calculus in college versus being an engineer: math isn’t an “realistic” scenario of what you’ll do on the job, but training with it will help in numerous ways.If they were flying an A-10, I’d understand. But is this a realistic scenario for a Flanker? If not, it’s a waste of time. Yet it has become iconic of the PLAAF.
However, they don’t have the same restrictions towards AAMs. There has to be more to it than the 2 reasons you listed.
Furthermore , it makes for rather bad publicity as it portrays the PLAAF as a force who’s ground attack doctrine is still stuck in the 60s.
PLAAF may not have the same restrictions with air-to-air ammo, or they may have them. Regardless, a2a and a2g are two completely different directions and it is impossible to use the lack of censorship on one to justify the absence on the other. There may be other reasons to the ones I listed above, yes, but they still stand as valid reasons.
As for the bad rep, I don’t think PLAAF cares what people think. In fact this censorship on a2g capabilities may be intended exactly as a method to lull adversaries into an inaccurate evaluation of their capabilities.