Not sure I follow. If by advertising code you mean plugins that are merged into the core product vs remaining optional add-ons/installs. If we go back you will find a variety of “Advertising code” was merged in core.
I can see from the DeV team perspective that many of their plugins may have started as plugins to allow more flexible testing before making it integrated in the core program.
I can appreciate like any software there is often features ppl might not use and choose to disable it and up to finding ways to uninstall features.
While I will admit there are a lot of recent merged plugins that I likely would not use. But having a simple disable and filtering them out is something good for all.
I understand that in part as stated by the team the intent is to make things easier with add-ons for self hosted.
Now imho the admin interface should be more customizable like it once was. As this can also help with ppl migrating from another platform by being able to load an admin there that is similar layout as the platform they are coming from. Much like how Linux does this with some mimicking other OSes. But that is another topic. 
I can appreciate the feeling that discourse might be starting to head towards bloatware. Reactors demonstrated how much leaner Windows NT could be.