If products have to compete on their own merits, rather than leaning on other aspects of a larger bundle, then software and products get better for all of society.

For example, if you were allowed to install any car OS you wanted, rather than forced to use the manufacturers, car OSes would improve significantly. Some people will buy a car for the hardware, despite terrible software. This is bad for the evolution of car software. If a manufacturer was forced to compete, they would have to invest more heavily in improving their software... or simply cede control of the OS to a better implemented third party one, and focus on the hardware. Both outcomes are better for consumers than allowing anti-competitiveness via bundling