is this a bad take

Probably - at least from a historical point of view. Historically anarchist communities have been established both in rural and urban areas; just depends on the material context.

It's sort of a catch-22 - cities often are more left-leaning for a number of reasons:

• large populations sustain a wider variety of industries and allow for more ubiquitous amenities and technologies, but tend to exploit proletarian members of society
• cities attract groups from other regions and cultures leading to increased familiarity with the unknown/other
• urban cultures are often on the cutting edge of progressive thought and new-wave ideas - think Viennese coffeehouses

However, they're built around hierarchical structures such as often-bureaucratic councils or some administrative structure embedded within the state, and have geographically alienating centres with higher land values and so on.
You have more to compete with in establishing a cohesive anarchistic society, not just the local government or the police, but other liberal and reformist groups that seek to redirect class-solidarity and struggle towards performative, superficial or otherwise dead-end issues and solutions.
It might be true that it's easier to realise an anarchist community in rural areas, but without technology and manpower the rate of growth towards communism will be slow. Likewise, it might be more difficult start in cities, but if the ball is set moving, overall progress can be very significant.

Call me a hopeless optimist, but I don't see the value in writing off one approach or another - synthesis ought to be desired when possible (but then I am a synthesis anarchist), i.e. por que no los dos?

Regarding Bookchin's libertarian municipalism - my immediate concern with it is that in essentially all anarcho-communist theory, a starting prerequisite is defeat of capitalism - at least on the small scale in an isolated city for example.
This could manifest in the form of workers expropriating their workplaces en masse, and assemblies being established to acquire and distribute resources in lieu of the market, and to provide essential services in lieu of the state etc.
Libmun. is essentially in reverse: take control of the city's power structures via electoralism, and utilise, effectively, the organs of the state to carry out your socialist whims - hence the reluctance by international anarchists to adopting Bookchin's theories wholesale.
Should you define municipal structures and elections as 'statist' or not?