I also have the theory that having an app/software starting with A, B, or an "alphabetically first" letter was noticeable in the past. Nowadays things are usual

I also have the theory that having an app/software starting with A, B, or an "alphabetically first" letter was noticeable in the past. Nowadays things are usually sorted "algorithmically", but it was common for stores to list searches with some alphabetical score, which meant that those apps were usually shown first. Even now, for example, if you go to Play Store and want to know the apps that you had but are not installed, the default sorting is by name.