It's an asinine grind already to just get enough masterwork cores to turn a weapon into a masterwork you already have. It's even more asinine to only give you 1 - 3 cores from a dismantling a masterwork weapon when creating it costs 10.
Now Bun-effin-gie makes us grind [b]even more[/b] to get cores to reroll guns, and get more cores to reroll them again, and again, and again, until finally and with a lot of luck you get the roll you want. I spent 15 masterwork cores until I just had faster reload on my Better Devils. HOLY EFFIN HELL, I hate you for this, Bungie!
So Bungie, remove the masterwork reroll mechanic, and add all available masterwork perks as extra perk column you can chose a perk from just as it is already done for the regular gun perks.
And stop the f* giving something to the Destiny 2 community with one hand and then turning around and taking it away with the other!