This place does seem to be uniformly wealthy, almost antiseptically so since Sandy destroyed the place and so the rebuilt mansions are all of the same vintage. That said, you still have the servants who live in the maid's room or suites, or above the garage.
Yes, I found the place sterile and loathsome. The vibe is it's for a bunch of investment bankers who skipped taking any humanities courses, hate paying taxes, and intimately know the ins and outs of the carried interest loophole. There might be a few math nerds mixed in who write algorithms for instant computer securities' trades to exploit perceived inefficiencies in the market. That is a "thing" now. Eww!
Oh the beach is all closed off its entire length to the public as well. Zero parking, and almost no beach access easements. You are just not wanted. Go to Coney Island if you want to get wet.
Deal is a very unique locale. It sports the highest percentage of Syrian ancestry of any municipality in the United States, owing to its large Syrian Jewish populations. Plenty of synagogues in the town, along with the huge McMansions.
I don't know where the Syrian Jewish make their money, but I don't think the town's strictly for investment bankers and trading quants. The nouveau riche vibe of the town might be from that source, because it is not old money WASP.
The beach, btw, is open to the public for a $10 fee. Worth it versus nearby Belmar or Asbury Park, since it is never crowded and the local bathymetry makes for bigger waves than other towns.