Wow, this really got out of hand, and a lot of these arguments are based on really silly assumptions.
The assumption that Smogon is at all concerned with emulating the gamefreak established wifi-meta isn't really founded.
This isn't even a debate about whether or not people should be able to simulate level 50 battles, it's whether or not SMOGON SHOULD MAKE IT THE STANDARD. The only reasoning is that it should, is so that it properly represents the wifi meta, and brings the community together through that. That, along with the fact that it would make it easier to simulate teams for people who play wifi.
Now, please correct me if I'm wrong, but neither of those things are fundamentally true or good enough reasons to make such a huge change to standards that have been in place for five generations and over a decade. That's not me being too stubborn to accept change, that's me thinking that your reasoning isn't GOOD enough to merit the change.
At the end of the day, Smogon is not inherently tied to any Nintendo tiers and metas (this is made obvious by the fact that on PS there are OU/RU/etc tiers, and VCG tiers that are separate). That, and why in the hell should Smogon care about your convenience? Smogon should care about what Smogon HAS cared about for a decade; the most competitive metagame possible that is democratically decided by the users and the choices they make when building their teams (usage stats defining tier).
So, unless anybody can give me a reason that makes competitive battling as a whole BETTER because we shift to level 50 as the new norm for simulation battle, I just don't see why Smogon should change to it.