Those are reasons why it’s not being addressed effectively, not why the problem exists in the first place.

• Are these homes bought for investment that can’t sell for the amounts the owners want?
• Were they inherited and being held unsold due to being tied up legally?
• Are they unsuitable for human habitation, either because of neglect or changing regulation?
• Are they simply temporarily empty due to “housing purchase chain” problems?
• Is the market undervalued?
• Has some rich supervillain bought up a few million homes just because he hates poor people that much?

The article proposes a question and then fails to answer it.