I'm not debating that higher temps won't affect the life of the card. I keep my card running at < 60C myself. I wouldn't dream of running them at 110C and wondering why they burnt out after 3 months.
However, the argument FOR the necessity of lower temps lost credibility when the same people posted stuff like this:
The other part has to do with the toxic fumes the card will emit at the higher temps. This never gets talked about because just like smog/pollution, cell phone radiation, GMOs ect., they are all supposed to be "safe".
It just sounds a little too panic-y, and sounds like you frequent conspiracy theory sites. The average person will not accept this as a valid argument.