It's a bad argument, because validity of a critique is not predicated on critic's life choice. It's like arguing that you cannot critique a movie because you have never made one.
It's not a critique of the idea alone, it's forcing it into context.
If we take a common example of how I've seen this play out:
A: iPhones and Apple are evil because they require child slavery.
B: But.. you own an iPhone?
A: Oh so I'm just supposed to go live in the woods?
I don't think B supports child slavery. B is pointing out that even people espousing this idea participate in the system because the alternative (not owning the iPhone) results in a worse outcome.
> It's not a critique of the idea alone, it's forcing it into context.
Exactly. But switching to individual context around societal question is the problematic argument here. Properly contextualizing means to use individual cases to explain impact, but that is not done here.
Society is formed by many individuals, and it doesn't necessarily matters what most of them do to address a particular problem. We have division of responsibility.
