Well, I do not think it is an absurdity. Both is testing of software. Let me explain why…
Testing games or PC applications for user perspective is not difficult. You need a guy (tester) and a computer with installed game or software you want to test. Then there are some ways how to test desktop apps and games. You can let user play the game and make him report bugs he will see. Or you can make a scenario for him to test (like go there, open this door, talk to this NPC and select this dialog option). Or you can let him to do the strangest actions he can think of to try to break the game. … and report issues he finds.
In testing ECU software situation is much more difficult. After software is ready for testing you can not to use it in real car! So you need to test it without a car. Ok, now you have to make the ECU think that ECU is instelled in car. You have to make ECU think that car is moving, that other ECUs can comunicate with your tested ECU, your tested ECU needs to read output of sensors in real time… and you have to create all these contidions in the lab. So you need a software model of a car, its sensors and systems behavior to feed the “fake - real” data to ECU during testing. After you do all of that you can begin with testing of ECU software.
For every test you need to have specification of preconditions, test actions and expected results. If the test fails there is a process how to ensure that bug will be fixed and you test again if bug is fixed. And do no think that ECU software is something simple like 20 lines of code that start and shut AC.
So my point was that for testing PC software you need just PC + “one guy” tester without any knowledge about the internal functions of software he tests.
For testing ECU you need lot of people with know-how + special equipment. In most cases in ECU testing you do not have a PC screen with result so you need to evaulate the results of the test. In PC game you can see the result instantly.
So… my point is to say that WH develop the desktop software and they are not able to test it even if it is not such difficult.