Spielberg makes big movies (or at least he used to, recently WoTW was one of his only big ones).
Now, I wasn't defending the script of the movie (while I love it, here it doesn't matter, and quite frankly, this is way to objective for me to question your taste here, or you mine

).
But the SFX. And while I agree SFX aren't necesarry, they are Mr. Spielberg's strength. He excels in using them, always have, and with WoTW, imo, he proved he always will.
Give 100 millions for FX to the director of thirteen floor, and there are a lot of chances he will not be able to handle it. Give it to Jackson, and he will go overload. Same with Micheal Bay and so many others. But with Spielberg (and again I wasn't talking about the story here, why are people always bringing that up when i'm defending Spielberg's use of SFX ?) you believe in what you are seeing. That first Tripod attack in the street ? Good lord, we where there! There really was a tripod coming out of the ground.
And imo, that's what's missing in most big SFX movies out there. James Cameron was one of the other few ones to equal Spielberg back in the days. Lucas too 30 years ago.
But things have changed. The new young directors are going overloard with the invent of CGI, and while Spielberg knows how to balance real with not real, most of them don't. (King Kong is a great exemple of that, while Lord of the rings was a far better mix of real and SFX than Kong was)
I see very few excuses when you have 3 years and 200 millions to make a movie, and it isn't nearly perfect in the SFX. Very few excuses.