Sam's career vs. Denzel's: Diluting the brand

Both are powerful, commanding black actors, but Sam doesn't quite have the same amount of respect as Denzel (no Oscars), and I think it's because he's overexposed himself. Whereas Denzel might take a year or two off between projects, picking carefully for maximum impact (give or take the rare fluff like Two Guns), Sam apparently cannot turn down a check or role, appearing in every kind of film there is, from powerful drama to superhero popcorn flick. In fact he hasn't done a serious dramatic role since Rules of Engagement, and too easily falls into the screaming "eff you mothereffer" role that comes easy to him. He already probably has enough money to last him a couple lifetimes, why not be more choosy?