XMR doesn't implement centralized mixing nodes... it uses ring signatures. As for your 'barriers to adoption' - who cares... it still makes DRK significantly inferior.
Is that why my DRK's retained it's value over the last few weeks while my XMR is now a meagre 35% of its 3-week-ago value ?
Or maybe it's simply because using XMR is about the most sh*tfest crypto user-experience anyone could ever have, including coin loss at exchanges due to the whole thing being workbench experiment that's not got a hope in hell of ever seeing any real world retail use.
Or maybe it's because they welded the "anon" layer to the "blockchain layer" leaving it paralysed on both fronts as far as the addition of any significant feature set goes.
Or maybe it's because of the torrent of mining supply that - in addition to above handicaps to value generation - requires a massive daily buy in to keep its market cap afloat (...which isn't happening)
Or maybe....shall I go on ?
Give me masternodes any day.