It essentially doesn't matter /why/ guns, tobacco, liquor, etc. are regulated by the government. That reasoning has no bearing on why Amazon doesn't sell them. Amazon is not a moral agent, it's one of the largest corporations in the world with a profit imperative to expand into as many product categories as possible in its goal to dominate e-commerce. Those government regulations make those product types conflict with Amazon's way of doing business and complying with those regulations reduces profit margins to a level where these products are unattractive to offer.
There's a moral-political argument which can be made, sure, but that argument isn't the basis for why Amazon doesn't offer these products, and /that/ was the assertion underlying the grandparent's analogy. It's simply false.
Substitute Amazon for local pharmacy, grocery store, or gas station.
Look, the point isn’t to talk about gun rights. The point is that Parler was the toxic runoff from 4chan, Facebook, and the parts of Reddit it deemed too toxic to keep. Facebook is 99.9% reposting of random memes. It’s 0.1% is doing a lot of harm, but by and large it isn’t obviously designed to be a white supremacy platform, it just happens to be used that way by a decent number of people. And that’s my point: guns are designed to kill things, not to cut salad. Knives are designed to be tools that are more often than not used for peaceful cooking, and sometimes misused to cause harm. Trying to turn this into a “guns don’t kill people” debate is pointless. It’s outside the scope of the analogy of why Parler was seen as a harmful thing while Facebook wasn’t.
I think rather than trying argue your original analogy was relevant and useful, you should instead simply admit that it was a bad analogy using an (intentionally or not) inflammatory and afactual comparison that detracts and distracts from the point you are trying to make. It's pretty clear that you're trying to make the point that Facebook is a platform for mostly benign things which as an ancillary has functionality that can be used by extremists, while Parler is specifically a platform built for extremists. You're doing a pretty bad job of trying to make that point by over-focusing on a bad analogy.
I'm not sure that's actually accurate. I think it's strongly debatable as to whether or not Facebook ever had any positive intents as a platform. Arguably, Facebook started as a way for predatory men on college campuses to stalk attractive women and comment on their bodies, which I'd be hard pressed to classify as a positive intent. Developing from that, Facebook has taken as many actions as possible to drive user engagement, including actively spying on their users to do so. Not only is the spying itself user-hostile, but the actions taken to drive user engagement seem to greatly emphasize and create rage, lust, fear, and other negative emotions in their user base. I'd be hard-pressed to classify any of this as positive intent.
I think you'll have a difficult time, regardless of the analogy you try to shoe-horn into place, arguing that Facebook suffers from unintended consequences when their ragebaiting mechanisms lead to political extremism and violence, and that Parler was intending that a platform designed for free speech resulted in extremism. Probably the best argument in your favor would be to focus on Parler's genesis story, which seems to strongly indicate that it too was not formed for positive intents. I think a mostly honest take is that both platforms are negative in both their intentions and their outcomes and are directly toxic for a functioning democratic society. The only real difference between Parler and Facebook is that Facebook is socially entrenched and has a massive global user base and the revenue/wealth that comes from that, and Parler doesn't.
I will say that my analogy might not have been as universally accessible as I had hoped. Clearly not. I could have picked something like chemical compounds as examples. It is a sad state that so many people attach their identity as humans to gun ownership and I keep underestimating just how much some cling to that.
To your other point, I am not defending Facebook here. The question that was raised: how come Parler was deplatformed as harmful but Facebook wasn’t even though it’s arguably worse in absolute terms. My point was that it’s probably because in relative terms Parler was mostly seen as being used in harmful ways while Facebook is seen as mostly non-harmful with some harmful parts.
I stand by that assessment, as in why Apple and Google haven’t removed the Facebook app from their app platforms. I do wish Facebook would get reined in because it is not a force for good. I think there was a brief period of maybe 2-3 years when it was a net positive: when you could use it to simply connect with people you used to know and lost contact with. Initially it was a weird stalker platform as you said, later it turned into a combo meme machine (and a bad one at that) and a marketing platform. About the only parts of FB that I still find useful personally are its Marketplace which is an objectively better experience than Craigslist (though FB is ruining it with how it’s running advertising there that really messes up your searches), and Messenger (but only because I at some point connected with a number of people on there; I will likely be moving those conversations elsewhere since there isn’t anything special about the Messenger itself). It’s other two major properties, Instagram and WhatsApp, are useful for other things but also have their own major problems. Instagram I think is a flash in the pan until the current generation of users ages out of being cool and the next generation wants to move to a new platform simply because they don’t want to hang out with the old geezers. WhatsApp has a privacy problem by design and better alternatives already exist (Matrix, Signal).
But yes Facebook is basically a mostly bad for society platform, it’s just bad in the sense that fast food is bad, not in the murder is bad. We tend to react to diffuse bad influences differently than to acute ones.
