Nope.

Would a 75 Move Rule be better than a 50 Move Rule?

It should be this:

Would a chess variant with 75 Move Rule be better than chess?

So far nobody has given an actual game where changing the 50-move rule would arguable be good. Someone failing to checkmate with bishop and knight within 50 moves is pretty bad reason. The endgames where checkmate is only possible with best play without the 50-move rule are really rare. Even many winning 2 knights+king vs pawn+king endgames can be won without breaking that rule. A lot of theoretical examples were given, but can you find actual games?

You put it admirably succintly.

It shouldn't exist at all, I have a thread on it. 100 moves minimum should be the rule if any.

Wrong, 2 knights vs pawn can take up to 115 moves from seemingly normal positions.

The rules of chess are meant to cover all situations, so whether or not individuals can remember games games where a change in the 50 move rule would change the result is not very relevant. It's likely that most people who know how to play chess can't remember a game where the 50 move rule was invoked in the first place. 

How do you reach the conclusion that the endgames where checkmate is only possible with best play without the 50-move rule are really rare? None of the current EGTBs will answer that question directly?

In any case why should you legislate for best play? Good enough to beat your opponent should do.

Also, how many times are people going to continue a chess game for 1000 moves? Even the top grandmasters aren't going to try forever like that. So even if 1 or 2 games did, so what? Enjoy the unusual endgame, get some popcorn and pizza, gather around, and take advantage of your extra break in between rounds! It's probably be the most interesting game you ever saw (most people don't play Q v Q for 1000 moves)

Yes, and as we've been discussing earlier, there are some pawnless endings which take 500 moves. So, the real question is, what is a realistic limit, given the time constraints in tournaments these days? If you don't have increments or play something like 40/2h > 20/h, it'll be virtually impossible for anyone to keep score for 100+ moves in a 2N v P and thus unable to make a claim. There are quite a few entirely plausible endings, such as R+N v 2B and R+N v 2N or R+B v 2N where the win is close to 150 moves and over 200 moves, respectively. What is a realistic limit?

Furthermore, the position which takes 115 moves has the white pawn on a3/h3 (or a black pawn on a6/h6). Over those 115 moves, the pawn is not standing still, so the 50 move count restarts.

Sorry to be finicky, but the rules of chess are not written to cover all possible situations. That's explicitly stated in the preamble to the FIDE's Laws of Chess.

Touché. But they are written to cover all possible situations of the kind we're talking about.

@Numqam

Not at all - see my post #51.  Players need only note the position when a new endgame appears and the arbiter compares that (or the position at the time of the last claim) with the position at the time of the claim. Also these claims hardly ever come up .

What you say about DTM staying the same will obviously be the case, but if it's the same when a claim is made as at the start of the draw period and for the same side then the draw claim will succeed, so the game is limited by the rule. That's the point of it. The same is true if it's been drawn throughout. See my penultimate example in #51. 

My suggested rule is intended to curtail pointless games while allowing mates to be completed if the player delivering the mate is making steady progress toward victory. 

Once again, you're not making any sense. How can a new endgame come up? What's happened? A capture or a pawn move? If not, please define 'new endgame' more clearly.

Yes exactly; a capture or a pawn move. How else? Why does that not make sense?

In practice they would only need to note the positions where a claim would be on the cards. They could always recreate these positions.

If there's been a previous ('last claim') claim, and then a new (by your definition) endgame appears, the 50 move count restarts. By which time the first claim becomes irrelevant.

That said, I still don't see how your idea of progress can be incorporated in the arbiter's judgement without him/her having a look at all the 50 previous moves when one player claims a draw. You cannot say that moves between the position at move n and the position at move n + 50 are irrelevant. How do you judge progress by looking at the positions 50 moves apart? You have no idea whether the player has followed a plan or it's just happenstance, even if s/he's has come 10 moves closer to mate.

RubenHougenhut: Yes, and that rule was of course scrapped relatively quickly. I don't even remember how long it was in place. There's no reason to go back to previous erroneous ways. (Back in the olden days you were allowed to offer draw when it was the opponent's move, for instance.) However, as I've pointed out repeatedly: if the arbiter rejects a claim in a KBN v K endgame on the basis that progress is being made after 50 moves, how far is the player likely to be from mate? Probably not more than 5-10 moves. It would be a very strong indication, in my view, while 20 moves away arguably doesn't even represent progress. Once you've herded the the king to the edge of the board you're about 20 moves away. If you need 50 moves to achieve that, it would strongly suggest that you don't know what you're doing.

Please read #51 and think about it. The rule is not interested in how accurate the play has been; only if the player who is claimed against has or has not improved his position by at least one move. As I said the arbiter is not intended to exercise his discretion.