Absolutely nothing. It's really strange that HN is filled with people who think they're experts on nutrition, even though their beliefs are often directly contradicted by scientific research.

http://www.hsph.harvard.edu/nutritionsource/fats-and-cholest...

There are absolutely no scientific citations in what you posted. The link between saturated fat and heart disease has been debunked repeatedly. Ancel Keys, the originator of the saturated fat = bad meme has repudiated his own early research.

When done in moderation, absolutely nothing :

http://www.livestrong.com/article/459116-can-you-replace-veg...

I think there's a perception of bad taste with canola oil, but in my experience, this is due to cooks inexperienced in cooking with canola oil. There are temperature and duration changes that must be taken to account. Some recipes need adjusting and calibration and that takes a bit of experimentation. Not everyone has the patience for that or is willing to research the differences.