10 000 years I mean come on, seriously I'm not saying we're the pinnacle of perfection but sweet jesus we've come far, hell we have gone farther than any other species could have glimpsed. Try to count to 12 Million and tell me when you've stopped and decided to go about living your own short life, do know that things will change though.
As far as the necessity of it all goes please consider what is unnecessary about it all? In the grand scheme of things I personally believe Humans are much better than this whole thing, this planet, or solar system. I'm all for preservation, just be rational about it. Of the top 100 things people are doing to destroy the environment and the planet, how can it even be possible seal clubbing would be on there. These native seal hunters aren't up there mowing through the whole herd, but I know if there was a little seal farm up there and pretty little moccasins got shipped all around the world in fancy ozone damaging plastic wrap I wouldn't here word one from USA Today?
Sorry,I feel you mis-interpreted the 10,000 yrs thing. That was an irrelevent number. I am agreeing with you on that part i.e veganism would not have worked 10,000 or 100,000 or 12,000,000 or [insert arbitrary evolutionary timescale here] years ago. My perspective is that although [action] may have worked [arbitray] years ago or even been necessary and desirable does not automatically justify it now.
'We've always done it' is a poor argument for continuation of a morally questionable action.
Regards the 'top 100' bad things argument.
If there are 10 murders and 1000 burglaries in your city,do the police ignore the burglaries until the murders are solved? If there are millions of tons of pollutants being dumped and thousands of seals being clubbed do you ignore the seal clubbing until the pollutants are gone?
It's also a question of 'being ABLE to do something'. E.g. I can do very little or, more likely, nothing to stop the next million tonne oil spill that hits the headlines but I can stop wearing fur/leather.