Wasn't that actually Santa telling Donner he should be ashamed? I laughed at that too when I first saw it, but now that I look back on it, there I believe Santa was calling out Donner for what he did to Rudolph.
Donner was telling Rudolph what he needed was self-respect, just wanted the best for his son, had good intentions but came off as too harsh.

It is because this movie was made in 1964 before snowflakes and safe spaces.
My son and I laughed when Donner told Rudolph that he should be ashamed for having a red nose.

No kidding. He was rude and dismissive to his wife and the elves and all but discarded Rudolf as he as saw him! What is the deal?
Santa's a busy man with an extreme responsibity. I get that, but would it have hurt him to be a bit appeciative of the effort everyone else was going to?

That kinda makes sense there, but honestly I think most of Santa's crabbiness (like "That elf song is driving me crazy!") is more for comedic effect. I'm guessing Santa gets in a bad mood close to Christmas Eve because getting ready for Christmas Eve and being an extremely busy man can be very, very stressful (though I heard an "Iron Man" song parody where they said Santa "only had to work one night each year!"
), I actually felt it this year as I've had to work a lot and I didn't even get my tree decorated until just round about an hour ago today. Santa's probably skinny because he took his busy side to an unhealthy degree
I can see them as the same Santa, to me shows even he's only human despite having his magical powers and sometimes we don't always act, well, perfect. Then again, the two Mrs. Clauses are different

True, but this was Rankin-Bass' first attempt at the big guy. Their later specials showed Santa in a much more positive light. I think they were just focusing on Rudolph and not giving enough thought to who Santa was supposed to be. It's all supposed to be continued, but it's hard to think of this Santa as the same nice guy in Santa Claus is Coming To Town or many other specials. In Rudolph and Frosty's Christmas in July, I think they attempted to explain this discrepancy when he and Mrs. Claus talk about how he gets in a bad mood when it gets close to Christmas Eve.

"All of the other reindeer used to laugh and call him names. They never let poor Rudolph join in any reindeer games"
The reindeer are suppose to be mean to Rudolph a lot of this movie is taken from the song. The whole film is about being a misfit and how misfits can overcome. True to real life - people will make fun of others who are a bit different.
Santa? He's just a grumpy old man that gets his Holly Jollies out of Christmas - but maybe not until that time! Hahaaaaha
"I am invisible, understand, simply because people refuse to see me." ~ The Invisible Man

That's a deer-stalker hat? Oh deer!
But I did read that that type of hat is popular to wear because of Sherlock Holmes, and they must have thought Santa would look cool in that.

worse than that, he wears a dear-stalker hat, and wears it in the first scene he appears in when he visits donner and the baby rudolph, talk about tact-less

Actually, now that I look back on this, I see Santa's mad outburst at Donner as
Santa calling out on Donner for how he was treating his son
. You wouldn't like it if you saw something like that, and nor would Santa. And at least Donner realized how bad he was acting despite his good intentions. I feel a lot of people misinterpreted that scene though.
Oh well, it's just a kids' special, and a darn good tootin' one too.
I can understand why you'd feel that at the end.

I only think Comet was a jerk at all. And I don't think Rudolph would
ever
say anything like beep you Santa", because that's not his character.