The requester being snarky is obviously not a valid legal reason for Facebook to not follow the law. But the people who fulfill these requests are human, so you should expect that acting like a jerk probably won't help.
Further, Ruben is mostly being snarky to lower level Facebook employees who probably have little say in Facebook policies. Don't shoot the messenger. This is like being rude to phone support staff because the product is bad. It's not the phone support people's fault. Let's assume good faith on the part of the low level employees. Ultimately the people fulfilling these requests are probably not given enough resources to fulfill all valid requests (this is true for FOIA requests in my experience), so they have to think of (literal) nonsense to deny them. They might even have a quota. Do you think snark is going to help in this situation? I don't. And I think reality is close to this situation. Ultimately the higher level people who set the policies and the budget for the GDPR/FOIA/whatever department are responsible. (And I don't think being snarky to the higher ups is going to help either, incidentally.)
Further, Ruben is mostly being snarky to lower level Facebook employees who probably have little say in Facebook policies. Don't shoot the messenger. This is like being rude to phone support staff because the product is bad. It's not the phone support people's fault. Let's assume good faith on the part of the low level employees. Ultimately the people fulfilling these requests are probably not given enough resources to fulfill all valid requests (this is true for FOIA requests in my experience), so they have to think of (literal) nonsense to deny them. They might even have a quota. Do you think snark is going to help in this situation? I don't. And I think reality is close to this situation. Ultimately the higher level people who set the policies and the budget for the GDPR/FOIA/whatever department are responsible. (And I don't think being snarky to the higher ups is going to help either, incidentally.)