Well, Grindhouse movies are made for a particular niche audience. And they're accessible because they have faith in their already-converted, nerdy fanbase, who takes pleasure in their low-budget, cheap productions and crass stories.
(And there's nothing wrong with that.)
The reason I made that point was not to say that there is something wrong with the B-movies. My point was that those directors aren't in any "cinematic greats" list even though their intention (accessibility+profit)
is same as that of Spielberg. Of course I am aware as I am typing that I am assuming that I know his real motive, which is obviously not true. However those two aspects were pointed out by you in his defense. Also there might be some other redeeming qualities in his movies, but lack of impact (my point) was quickly treated as a not-so-strong point in the context of a grand purpose of accessibility and profitability (by not only you but also others, 24fps among others).