Frankly I'd rather them embrace it. FFXIV does that where you can't even test changes before they end up going live. Granted, FFXIV's internal testing team is pretty stellar (compared to WoW, who has fucking PTRs and still has more bugs than a Mississippi river bed.
My point being, with Blizzards "quality" bug control along with the inability to test any of their changes, focusing less on the PTR would be a disaster.