It's not "entitlement" to share my purchasing preferences with Proton. I am glad to pay for Proton Mail subscriptions, but I am unwilling to pay for Proton Drive subscriptions (including Proton subscription bundles) until Proton releases a free and open source Proton Drive client for Linux. This is a perfectly rational position to take, since nobody wants to pay for things they aren't able to properly use.

I'm not the only one who is demanding a Proton Drive client for Linux. On Proton's user feedback forum, this feature is the second-most highly voted suggestion for Proton Drive: https://protonmail.uservoice.com/forums/932839-proton-drive/...

While you're certainly able to communicate with Proton however you like, it's not anyone's place to tell me and other Linux users what we can say to Proton on an online forum or whether we're allowed to express annoyance. There's no better way to let Proton know how I will vote with my wallet than to tell them directly.