Here's my brief against Montgomery County:
1. The roads are awful
2. The drivers are the worst in the country
3. Taxes are significantly higher than neighboring jurisdicitons such as Arlington, yet the level of service is lower.
4. Car insurance is goddawful expensive in Montgomery County (my car insurance was $2k annually while it was $800 annually at its highest in Virginia)
5. The housing stock is poor, and the lots on which the houses reside are stingy.
But I come from Northern Virginia and there is simply something that is hard to explain but we from Northern Virginia find Montgomery County unappealing and the feeling is reciprocated. Bethesda is actually a pretty nice place. It's very expensive but it does have close proximity to a lot of cultural amenities, it has convenient access to mass transit, it is right on the border of the city and has some wonderful dining options. It feels sterile to me but sterile is better in my view than some crime-ridden shithole.