The Line is actually a massive success. Saudi Arabia has a massive problem, in that it is dependend on oil and gas, while radical Islam causes a lot of problems for switching to a more sustainable future. Especialls womens rights have improved a lot(still bad, but better). If you ban married women from talking with unmarried men, travel without guardian, drive a car and so forth, you are not using half your potential work force. These sort of strict laws also make the country less attractive to outside visitors. That however is required, when you have business travel and tourism.

If you want to avoid a big backlash, you need to bring the Saudi public on your site and crack down on the most radical faction. A utopian project like the Line is perfect for that. It can inspire the public, while distracting from the crackdowns. It also works as great advertising for tourism. If you are able to deliver something similar, then you have a pretty good product. That is not as true for the Line itself, but for other parts of Neom. A big port in the area makes sense and tourism on the Red Sea is big business in Egypt.