To justify their feeling of superiority.
Because they use a newer round that isn't much different.
But because THEY use it it's better.
"30-06 is just sooooo boring. Not worth a crap really.
I, ME, #1, use a 270, 280, 33-06 35Whelen......
to hunt deer, bear, elk. Out to 250 yards!
It does soooooo much better."
It is the boring baseline.
But consider that.
Flatter,
Faster,
Bigger hole,
Than the 30-06
People try to justify their choice by telling you what it does better
than the Old Warhorse.
The funniest is something like a 338 Federal,
Or the 30TC.
"As good as the 30-06!"
Well?
They fizzled out in less than 20 years.
Actually they never ever burned bright.
The old stalwart?
115 years old.
And still a standard chambering in sutible guns.