I personally think Brian Armstrong and Coinbase have been a net negative for Bitcoin. And most likely will continue to be. Armstrong has worked as hard as he can to build a cantillon type structure in the crypto markets, basically actively working AGAINST one of the key innovations Bitcoin brings to the world.
It's the classic question. Is he evil? Or just dumb?
A lot of newcomers to Bitcoin don't know this, and a lot of the past gets memory holed and forgotten.
In the first year or two when Brian A. was getting Coinbase up and running, he was interviewed on a few occasions. I remember one interview very clearly where the interviewer asked him point blank if he had any interest in altcoins (this was even before the term "shitcoin" became a thing), and Brian flat out, without hesitation said "No, because I don't think that they have any value beyond what Bitcoin offers." He then went on to say that Coinbase would be exclusively focused on Bitcoin and nothing else.
So he was either lying then, or he his lying now. Perhaps the plan all along was an eventual bait-and-switch of the public. Or perhaps he has never been in control of his platform, and it was always the VCs calling the shots behind the scenes (my bet is on this). No matter what he might now say publicly, I don't believe that deep down inside he thinks that shitcoins have any real value at all.
Either way, I agree with you that offering and promoting shitcoins has definitely hurt the Bitcoin movement, and is completely antithetical to Bitcoin's long-term mission. His platform of promoting and selling shitcoins will continue to distract and lead the dumb, get-rich-quick mass public away from Bitcoin, and they will continue to get scammed and lose their wealth.
An analogy is that it's like a website that supposedly promotes health and fitness, but also selling heroin and donuts on their platform.
It's also why you can't place trust in any celebrity or personality that's a backer of Bitcoin; you can only place trust in the asset itself.
Brian Armstrong was a prominent Bitcoin supporter until he went full shitcoin. His shitcoin casino generated a lot of money, he bought a $113 million Bel Air mansion in L.A.
The quest for new n00b bagholders will go on for some time, with clever marketing many idiots will end up losing their money.