Chief of Naval Operations Adm. Jonathan Greenert makes the very valid point that having a very expensive aircraft to deliver a cheap bomb does not make economic sense. If the risk is that high, send a Tomahawk. If the risk is low, why limit your self to small internal loads only?
The size of the F-35 internal bay is academic - war technology has moved on to make stealth of marginal value.
Where it should still be useful is in A2A and anti-shipping, which suggests that UK's choice of the F-35B was the better one.