People just don’t like change.
That glosses over the question of how to name the streets, a question quite conductive to nasty political fighting. Maybe that already happened.
Change is life. When you're afraid of change....
I'll go you one further: Constant change for the sake of change is the mantra of those who would like you to not have the peace to form a personality and coherent convictions in your mind, because you must not have what they discarded or never had in the first place. That's just as much a slogan as "change is life", but good luck with easily disproving it.
> The ideals of homo faber, the fabricator of the world, which are permanence, stability, and durability, have been sacrificed to abundance, the ideal of the animal laborans.
-- Hannah Arendt, "The Human Condition"
And they are no necessity, which is why it’s a vote in the first place.
In the best case scenario they are very safe choices, that are then reused basically everywhere, sometimes in several places in the same town.
I have seen countless of french towns with "Général de Gaulle" named variations of streets, places, rotaries, small passages etc. It's so overused that it doesn't make sense anymore, people mess with the categories very often (was it a street or a boulevard ? who cares ?)
In the worst case scenario, street names are chosen according to the heroes of the times, or some other political figure that is/will be highly controversial once it has its name on a plaque. It then becomes an endless battle to find a compromise, avoid further cultural frictions while choosing names that make sense for the town.
For instance in former colonies, street names have often been set to colonial personalities. Some of the (wealthy) residents still support the naming, while others (sometimes minorities) will object to the cultural signification of having these names around for public areas.
These issues are just symptoms of deeper problems, but not using names in the first place just makes things easier.