I mean, if we had no other beautiful water vistas with different landscapes and views and unique looking boats at WDW then id be more upset.
But like,
World showcase
Coronado Springs
Disney Springs
Saratoga Springs(lotta Springs
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)
Port Orleans
Old Key West
Monorail Resorts
Wilderness Lodge
Fort Wilderness
Epcot Resorts
Caribbean Beach and Riviera
Animal Kingdom's discovery river and lagoon
And i probably didn't even hit them all.
There is SO MUCH beautiful stuff tied directly to rivers and lakes at WDW. The MK river isn't the only source of it like in DL( the Pixar pier area notwithstanding)
Ill miss the river, but i still have so much. I personally find nothing better than sitting on the beach at beach club watching the friendship boats with the boardwalk as a backdrop at night.