Nothing to do with “feelings” or “honour”. China was not “forced” either. Su-27 was best available fighter to purchase in the early 2000’s. Flankers were not copied, they were licensed and the technology was transferred. At some point, Chinese development in many fields progressed rapidly ahead of what Russia was willing to export (Look at Su-30MKK radar vs MKI for India). Thus modifications outside the scope of the original agreement were made, which elicited the Russian grumbling mentioned above.my feeling is that China was forced to copy and then modify the Flankers at a time when it had no other choice available.
What China did was to ensure China's own safety, by safeguarding its own airspace.
As such it is not an honorable thing to do by exporting your planes based on somebody else's IP, despite heavy modifications.
So unless Russia gives her blessing for export, China will keep her Flankers within China.
Beyond that speculation, there are a few simple facts that explain why there are no exports of Chinese made Flankers.
1. Would still need Russian engines.
2. Market for expensive heavy fighter is limited to begin with, the advantage of Chinese made Flanker would be things like AESA, which would only drive the price even higher.
3. Domestic demand limits export capacity.