The reason is that the always-camera-ready Ronald Reagan thought it would look good on television.
Thank you for all of the replies. Side comment from the book “Backstairs at the White House”: Jacqueline Kennedy went to a warehouse where old White House “stuff” was stored. She found several sets of White House china that had been retired because there were no longer complete sets (breakage, etc.). So she had it brought out for state dinners. She just used different sets at each table.
they don’t call sports winners now, they go to the white house.
A senior officer does not have to return a salute of a lower rank person but they normally do. A lower rank person has to return the salute of a higher rank person. Heard of a general who made people salute his car even if it was empty. Also heard of a guy in OTS for the AF salute a dominos delivery guy.
Nitpick: “He’s the Chief and he needs hailing” was the version at the start of that conversation, from the one who posed the question. The other President’s version, only revealed much later in the movie after they’ve earned each others’ trust, was “Hail to the Chief, 'cause if you don’t, then I will kill you”.
Here’s the two versions on the toobz.
Hail to the chief
If you don’t, I’ll have to kill you
I am the chief, so you better watch your step,
you bastards
I need to find out if that movie is streaming somewhere. Haven’t seen it since I was a kid, but I still remember the lyrics. 
I’ve read that this is the tradition that most Presidents dread most. It’s no-win for them: either they manage to get the ball somewhere close to the plate, in which case nobody cares. Or they throw it straight into the dirt or wildly off target in which case it makes that night’s news.
the old way was the president in the stands tossed ball to catcher a few feet away. Now of course they go to the mound.
That’s the ostensible reason, but the President is still a civilian and not subject to military protocol.
Powers &8^]
Returning salutes to soldiers.
That really irks me. Reagan started it, but it looks really stupid, and the sight of Trump doing it was stomach turning. I’ve seen old film of Eisenhower and Kennedy being saluted by uniformed personnel and they didn’t return the salute. The President is commander-in-chief, but he is still a CIVILIAN!
Absolutely. Someone should have talked Reagan out of it. This needs to stop. I think it undermines the sanctity of civilian control over the military.
“Pardoning the turkey” always bothered me because it just meant that a different turkey had to give its all for the cause. It wasn’t as though the White House was going vegetarian for Thanksgiving.
Watching the inauguration Wednesday, I noticed a military member saluting Biden. Biden did not return the salute. I see that as progress. (I can’t remember if it was before or after he took the oath though.)
Powers &8^]
The president needs to rescind or reactivate the Mexico City policy on abortion if they are a different party from the previous president.
I suspect the china thing will be done less and less frequently in the next few decades. But its paid for through donations. And there is a lot of signaling in it.
I understand that it is traditional for the President to send a congratulatory letter to any U.S. citizen who can verify they have turned 100 years old.
I suspect it’s all handled by White House staff, but my grandmother-in-law received one from Obama.
Clearing brush at “The Ranch”.
Yeah, I know, it was only really Reagan and the Bushes who did this. But I do expect to see it in the future.
That is one thing I do give Trump credit for, he didn’t go in for some of the heartland-ish photo op nonsense, because it would be off-brand. He was all suit & tie, or golf clothes. You never saw him posing in a plaid shirt next to a pick-up truck.
And what capital offense was the turkey guilty of? Is deliciousness a federal crime if you’re a turkey?
Although previous presidents had spared gift turkeys, it seems Reagan was the first to refer to it as pardon (as a joke), and George H.W. Bush was the first to do it regularly.
Most of these traditions got started by a president for whom it was great PR, and then his successors were stuck with it otherwise they would look like a douchebag. Woe to the first presidential candidate who fails to wear a flag pin.
That’s not a meaningless gesture that’s done just because it’s traditional. It’s an actual, substantive policy revision reflecting actual, substantive policy differences between the two parties. There’s definitely potential for absurdist humor in observing the two parties switching the rule on and off like clockwork, but the President definitely isn’t doing it “because it’s traditional.”