Interesting indeed.  as a child of the 60s and early 70s I distinctly remember our house switching over from lard to Crisco and Wesson oil. Seemed like lots of food was less tasty and 3 of us boys developed a "spare tire" around our waists.  

 A lot changed in the 70s and a lot of problems, coincidentally, came with them. Just completely swapping "vegetable" oils with something like lard/butter is kinda crazy the amount of change and improvement most people I've commit to it have experienced. There are plenty of other things as well, but that is definitely a big one in my experience.

This was one of the very first things we did when we started our journey about 15 years ago now. 

 I started cutting out “vegetable” oils a few years ago replaced with butter and animal fat. I feel much better since making the switch. I had a “cold” for the first time a few weeks ago after a particularly stressful week where I didn’t get much sleep. Even then, it was pretty mild compared to what I would have experienced back when I ate standard American diet foods. 

 I'm also not saying that rapeseed oil being put in everything is the source of ALL of our problems, btw. If you base a person's entire position and their thoughts off a single note with a single paragraph then you are bound to develop plenty of assumptions that have little to do with what they actually think.

I'm also perfectly aware there are grey areas, that the list of carcinogens is ridiculous, and that to "avoid everything" is an absurd statement. Very little of anything regarding diet can be considered "conclusive and undeniable" and yet everyone discusses it like it is, while its clearly one of the least reliable sciences and horribly difficult to control for because of the near infinite amount of other factors involved.

Which is why I think basic heuristics and common sense are the most important tools.  

 No but you constantly make out seed oils are in everything so what practical advice does that leave  people that haven't a clue about health decisions when they think most foods are bad for them from your doom mongering. I never ever make out it's easy, that's why I went into that line of work. UTXO was correct in the view that it's just over consumption of these crap foods. Are seed oils a contributing factor?....of course, like anything else that's over consumed. I can literally find any ingredient in any of the foods people eat in a paper somewhere that is harmful but you have to realise that most (not all) have little effect on human outcomes. Please bare this in mind. 

There is plenty of easy home blood tests you can do to track these things and adapt accordingly. And there are some simple adjustments from knowledgeable people that you can continue to consume bad foods now and then. Because we are human and there aren't many people that eat super clean 7 days a week. 

I've tested enough people and have collective real world results from thousands of others that have better biomarkers that do this than the people that just blurt out just stop seed oils. In fact, the majority of people have never done once single blood test to even evaluate what their status is, they just guess. You won't feel chronic inflammation until it's too late because it will have been building up for decades before.  

 You're missing the point, imo.  There was never a reason nor any benefit to having seed oils in our foods. Literally none. Of course you can consume them in limited amounts without great harm. This is generally true of like 959% of things that are toxic or bad for you. They only do significant harm in large amounts. But you can also eat almost all of the same foods withOUT putting canola oil in them. You can cook your food in lard and butter instead of seed oils. You can gear your diet toward healthy fats. This is what we did for basically always until very recently.

If the grocery store has something bad in like 90% of their products, then all you have to do is support and purchase the products that don't put this in the food. Viola. And it helps to solve a stupid problem that never needed to exist in the first place.

Of course you can just stop eating as much of something toxic and it'll do less harm, but it is not good for you regardless, and there's zero reason for it to be in our food. It isn't food, it's bad for us, and we should stop using it. The point of telling people is so they know. That happens to be a prerequisite to solving ANY problem.

For the record, it isn't that hard to avoid them either. You just have to be careful about picking stuff up off the shelf and you have to be cognizant of what you are putting in your body. You can also easily just ask just about any restaurant out there to "please can you cook my steak or food in butter instead of vegetable oil?" And like 90% will just say "sure." I do this everywhere I go. 

It's not that hard, but no its not going to come without any effort at all or in total blissful ignorance on the part of the consumer. 

 I know exactly the point. I'm well studied on these topics and had extremely in depth conversations over the years, I do however agree with alot of these things you've said in this reply though. We are all trying to help others be more aware. I personally think most do a terrible job of it with a huge lack of understanding and nuance.