You could see it as sticking the boot in, or you could see it as other sellers trying to get you to see that you're providing conflicting information in listings about stock availability and delivery times (quantity available & handling/estimated delivery time vs disclaimers in the description), and that sometimes buyer expectations aren't being met with the current listing method.

That gives you two options - keep doing what you're doing and wait for eBay and/or the buyers to change what they're doing, or change what you're doing. Only one of those options provides you with any control over the outcome, so I know which one I'd choose.