You definitely want a GM with a better draft track record, and the criticism in that sense is fair -- you want to see continued, sustained, forward momentum, and quick, decisive, and smart course corrections when you don't have that forward trajectory that gets you back on track quickly.
But some other realities: Reggie himself isn't solely responsible for making draft picks by himself in a vacuum. First round picks in general have about a 53% success rate -- and these are for widely accepted and lauded blue chip prospects. Let's not pretend that most draft picks hit across the board, year in/year out, for any team let alone the Raiders. PFF did a study last year, I believe, rating the previous 20 years of picks, finding only 7.9% of picks were either great or legendary, with 79.5% of picks labelled average, poor, useless, or DNP. Far from the exact science I see it expected to be time in and time out.
I also think that we're shortsighting this year's draft with Miller, Hall, Hurst, Key, maybe even Ateman. Jury is still out, probability is that they fall in this average-to-useless bucket given historical data, but they've all looked solid this year and seem to have a good base to build from. TIme will tell from this crop, but I'm willing to bet this will turn out to be Reggie's second strongest draft after 2014.