What you mention is a different scenario from a developer building an 8-story complex next to a 2-story SFH, and it's reasonable to think we (society) could treat them differently if we so chose.
What you are talking about has absolutely nothing to do with the article. The proposal says that there should be a maximum of 4 units (not stories) per lot plus an additional 2 units if those two units are rented out as affordable housing. The article shows that the neighborhood already has a 6 unit building with 3 stories. It's absolutely nothing new.
