I think that the reason, some people - my self included, prejudices can be explained:
We remember too well the days of our youth and the bullets commonly available to those who could not afford the partitions. (We shot 22 shorts because we couldn't afford 22 long rifles.) Some thought that cast bullets were as good as many bullets available and we started shooting deer with heavy cast bullets in the 30-06. There was a writer back then that liked heavy bullets and large enough cartridges to get the bullets to penetrate - what he wrote, he wrote with authority and it made sense. Then there was a famous writer that wrote "Bring enough gun". We saw failures of bullets that were too lightly constructed or poorly mated with game. I shot a pronghorn six times through the lungs before he dropped all the bullets went through the lung area (one example of a bullet that would not open up). The horns are hanging in my gun room now. I had a bullet get stopped by a doe's shoulder 165 grain in a 30-06 - it didn't pass the shoulder. I would not use that brand for decades since. My brother-in-law had a similar experience on a bull elk - same brand of bullet out of a 300 Win Mag.
So, with bad experiences brought deeply set prejudices, using a larger caliber and heavier bullet was often the answer. No one wants to relive bad experiences with bullets to fragile!
I mainly shoot partitions now (thanks to SPS) with interlocks second and mono bullets third. It's a 308 with Interlocks on deer this year. For elk, one of my most accurate rifle is my 300 Weatherby with 200 grain partitions, the recoil is negligible, so why not? But, I'll probably use a 270 with 160 grain partitions this year though, because it's a pound lighter and just as accurate.
