It's hostile because they're threatening to remove a payment option that is literally no overheard for them to implement (all the work is being done by coinbase, they just have to cash the checks like usual).

I am not angry in the slightest, I just think it was a poor decision by app.net to place the time limit and threaten the Bitcoin community with permanent rejection of Bitcoin if they fail to cough up the $10K within 30 days.