Not at all. It all depends on what you want and need.
I sell real estate in east central Florida, between the Atlantic Ocean and the Intracoastal Waterway, and one of our nicest waterfront communities is a manufactured home community on the Indian River for people aged 55 and over. The name of the community is Edgewater Landing
Many of the people who live there are active retirees, who value the amenities that it provides--a boardwalk and fishing pier, boat launch and boat and kayak storage facilities, tennis, a pool and spa, a million-dollar clubhouse with a kiln and woodworking shop, as well as many clubs and activities.
Another thing that enhances this riverfront community is that it's not a rental "park." If you own a home there, you own the land under it as well as the common areas of the community. So you are not subject to the whims of a "park" owner who rents you a "space."
Of course, like any type of housing, a manufactured home won't appeal to everyone. One of the main advantages, in addition to owning real estate, is affordability. Drawbacks can be difficulty obtaining financing and insurance.
In the end, only you can decide if a manufactured home is right for you. If you're looking for other types of prefabricated homes, you may want to investigate log homes (such as Timberline), Deck Homes, and Katrina Cottages. Good luck!