I got to thinking about the subject line on my flight back from the Bahamas this Sunday. I had an IFR plan on file and took off from MYAT headed to Fort Pierce. There was a decent cloud deck that limited my ability to climb to altitude without a clearance. Miami usually pick me up at around 5000' and I knew that climb was not going to happen. As I flew towards the US, I continually tried to raise Miami. As I got closer to Freeport, I tried them as well. Calls to Miami Radio were also unanswered. The weather had me deviating a little farther north than I wanted to go and I was stuck under a solid deck at 1500'. The closer I got to the ADIZ, the more concerned I became. I had a flight plan on file, ATC could most likely see who I was and I was not doing anything strange (other than flying at 1500') I finally raised Palm Beach appr. when I was about 30nm off the coast. They gave me a code and I went on my way. With ADS-B becoming mandatory, are flight plans for the purpose of transiting the ADIZ really necessary?