I think it is possible to acknowledge there is some "apples and oranges" comparison happening, while still recognizing that ME 3 MP was an objectively better MP mode than DAMP is.
I'm not upset about DAMP, even though I had a few overblown hopes for epic dungeon coop exploration. I don't know how many hours I ultimately played of DAMP, but it was more than enough to feel I had my money's worth from the purchase (I didn't buy it for the MP co-op, and I might feel differently if I had.)
ME 3 MP was ultimately much better than I think the vast majority of people expected it to be, and it had the combination of factors necessary to encourage a large and varied player base that, despite shrinking a lot over the last three years, continues to be sizable enough to maintain a thriving community.
ME 3 MP also has a much longer learning curve, and demands a higher level of reaction and skill at higher levels, making for a longer play life. I'm not saying this to be judgy - just being honest. I played bronze for months before I could reasonably hack Silver, and I needed help from BSN to learn to play Gold. While I can now play effectively enough to rationalize PuGing Platinum, I don't consider it worth the headaches because of the high difficulty.
In DAMP, I was able to make the leap to Threatening literally one week after I started playing, and it required no additional skill. All it required was unlocking a Superb Ring of Life Drain after about a dozen games. From there, Perilous was simply not possible for me until I had unlocked advanced armour and high level rare/uniques. It only took me a month or so to unlock at least one level 20 rare weapon in almost every category, and from there, I was able to play perilous, primarily on the strength of my high level mage staff and Trepanner's on a pre-nerf Archer.
DAMP is a fun way to pass the time, and I can certainly see why the community that still plays it ended up liking it more than I did. There are ingredients to build on for the future, and if one really likes DA:I, it will extend the replayability of the game, which is a good thing. But regardless of how much support either receives, or how many characters or powers or weapons get added, ME 3 MP's fundamental design and gameplay is on a different level from DAMP.