I think the point was to examine just these two politicians to show that the two messages are the same in different clothing. It wasn't to suggest that there wasn't alternatives.
I would even say that the alternatives have the same issue.
Politician C: I will make sure that housing remains affordable.
Politician D: I will make sure that your housing investment does grow.
But C is (loosely) the negation of B and D is (loosely) the negation of A. While there are other choices, the likely ones people vote are are the first group (A, B) verses the second group (C, D), normally with the options appearing in their nicer forms.
In short, affordable housing and having homes be worthwhile investments are at odds with each other in most issues.