Note that this is not always the case (airfare varies depending on many factors; ie. dates, demand, etc.), and there are also significantly more flight options/airlines available between MCO and the NYC airports..
Also, flying into TPA only works if you rent a car as it is a 73 mile drive between TPA and WDW, which is about 1.5 hours of driving time (+traffic).. This would not be a feasible option for anyone not renting a car..