Any opposition made it another target. Near
misses would splash water into the intakes which is bad news. Imagine clipping along at 300kts and having the port engines spit fan blades while
starboard were maxed out.
I wouldn't be too quick to count out the Ekranoplan and ground effect aircraft just yet. The various and wildly different implementations of these
technologies do offer very militarily significant benefits. Especially where naval warfare is concerned. Personally I can see some pretty compelling
reasons for looking at them as a potential solution for amphibious assault too.