The pressure from the device vendors to the SoC vendor to support the kernel version which was initially used for the SoC and fixing bugs and adding new feature is much bigger than the pressure to upgrade to new major kernel versions.
The board manufactures normally do not want to upgrade. I very rarely see that device manufactures are doing a major kernel upgrade when a new SDK with support for a new major kernel is available from the SoC vendor. This only happens when they need new features from the new major kernel which can not easily be backported and a very big customer is requesting this and normally they also need a good internal software engineering department.
The board manufactures normally do not want to upgrade. I very rarely see that device manufactures are doing a major kernel upgrade when a new SDK with support for a new major kernel is available from the SoC vendor. This only happens when they need new features from the new major kernel which can not easily be backported and a very big customer is requesting this and normally they also need a good internal software engineering department.