If a restaurant is one’s favorite it simply reflects individual preference of a particular type of restaurant. I would certainly not buy with intent of running it because it requires a very unique skill set to run a successful restaurant.
The decision to buy a restaurant will depend on many factors such as long term profitability, demand and competition in that area. I would also like to ensure that current cook, management and service staff continue to work under new ownership with same level of performance.
In nutshell, liking a restaurant is one thing where as decision of owning or running one should not be taken just because it is a your favorite.