Should GMs who fall below 2500 lose their GM title?

Or at least be on GM probation?

Should college graduates who say something stupid lose their degrees?

That's a little different because you can get multiple degrees, but there is only one GM title as it pertains to the main overall players. 

So, a better analogy is like a surgeon losing their license. That doesn't mean they aren't qualified to do surgery. They should just be on some probationary period. Teachers get re-evaluated (maybe not enough) to make sure they are still qualified. 

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"The titles are valid for life from the date confirmed."
https://handbook.fide.com/chapter/B01Regulations2017 

It is bad enough that an elder grandmaster falls below 2500, you do not need to strip him of his grandmaster title too.
A grandmaster has no pension benefits. He needs his title to earn some money.

Let us take an example: the recently deceased GM Sveshnikov
https://ratings.fide.com/profile/4100638

He dropped to 2456, so in your opinion his books should be by IM Sveshnikov instead of GM Sveshnikov?

If you are writing a book, your rating shouldn't justify the book.The content of the book should be judged. Why have any title preceding the author of a book? Do we say GM Carlsen took a poo? Or if he rushes to the toilet do we say "Magnus went to the restroom"?

If he was a grandmaster at taking a poo, we should say "GM Carlsen took a poo" and "Magnus is playing chess", for example.

It is like a Phd in chess. They had to be over 2 500 FIDE at certain point and get their norms along with it. In the same manner, as Phd you need to pass all the exams, contribute something to your own field and write a thesis to get a Phd.

You don't strip someone of their Phd because they are not contributing to their field when they get older. They earned it during their lifetime and will keep it. The same goes for GM title.

Why would you strip some 70+ years old GM? If you did, he would have to quit playing in tournaments just so he can keep his Elo and title along with it. 

"If he was a grandmaster at taking a poo"

No, we need to see the quality of the poo.

"It is like a Phd in chess." 

No, it's like the Heisman trophy. It's a recognition of some achievement. You can still be a better teacher as an IM. I watched Artemiev stream earlier today. Yes, he played well, but did he explain anything? No, James Canty is a much better teacher.

So, if your performance falls below some standard it should be noted.Otherwise, why rank GMs at 2700chess.com ? Are we going to allow 2000 GMs to exist?

"Why would you strip some 70+ years old GM?"

If that 70+ year old GM can't drive straight or see the road signs anymore, then their driver's license should be revoked.   

Sveshnikov is a legend of the game, and I think we should treat all Grandmasters with the appropriate respect regardless of whether they are on a winning or losing run.

GM is not like a trophy. It is a title. Here is the quote:

Grandmaster (GM) is a title awarded to chess players by the world chess organization FIDE. Apart from World Champion, Grandmaster is the highest title a chess player can attain.

The quote is from here:

https://en.wikipedia.org/wiki/Grandmaster_(chess)

As for who is a better teacher, that is meaningless. That title is not given based on what kind of a teacher you are. It is given for your playing achievements at one time. By getting it, you are recognized among selected few who managed to get to 2 500 FIDE and get 3 GM norms. As nobody can take away your norms you've earned, and nobody can put your peak rating under 2 500, nobody can take away your title (unless you are caught cheating or something like that).

So no, it should never be revoked.

No, that would be idiot and disrespectful.

Grand Master is only revoked for cheating, not a bad system. Keeping it that way seems to work well, why change?

Then how do you differentiate "GM who is playing like a GM today" and "GM who is currentlly slacking"?

We talk about top 10 GMs and note when they go below. We talk about Svidler dipping below 2700. We should at least do something about the "Used to be" GMs.

You differentiate them by their current playing strength which is there for everyone to see. You don't take away the title they've earned in the past. 

Imagine if Karpov or Kasparov goes under 2 500 FIDE one day. It would be ridiculous to strip them of GM title. 

"Imagine if Karpov or Kasparov goes under 2 500 FIDE one day. It would be ridiculous to strip them of GM title."

They are retired though (from classical at least).

Isn't this just the key difference between a rating and a title?

As your performance drops your rating drops as well. While your achievements remain unchanged. There are many titles or accolades that last a lifetime. Consider being a Wimbledon winner until someone replaces you.  It's perfectly fine to call someone a two time winner and three time finalist. Even if the last time they participated is a while ago. 
"Bjorn Borg , currently under probation, will lose his 11 grand slam titles, since he hasn't performed in the last four decades. After his Monte Carlo experiments in 1982 he failed to produce any results."

Ok, but take Pete Rose for example then. He achieved something great, was banned from getting into the Hall of Fame between from 1992, then in 2016 he was inducted into the H.O.F.

If we can call Magnus and Caruana super GMs, surely we can call 2500s who fall below sub GMs.  

that's just disrespectful

I don't see why it should be seen as disrespectful. You are just labeling what they are currently.

Just because you had a good year working for your company one year (made employee of the month a few times), if you don't put out the same work performance the next year you should get demoted. Why get paid the same for lesser performance? 

Super GM is not an official FIDE title. That is a key difference. People just wanted to differentiate those who are at least borderline candidates to be a world champion, so they invented this expression - "super GM".