In the coin collecting hobby it is possible to go to a bank and get a bag of uncirculated coins. A bag of pennies is $50 worth or 5,000 pennies. You can go through them at your leisure and select the 5 or so coins out of the 5,000 that might be strong candidates for a perfect grade of MS-70. And if you don't get any good MS-70 candidates in that bag, you can go back and back again to the bank to get more bags of uncirculated coins. The supply is virtually limitless. After all, they make something like 10 billion pennies every year.
You cannot do the same thing with casino chips. You cannot ask the cage to give you box after box of their unused chips. For one, they don't have them and secondly there is no reason for them to do so. Since the populations of collectible chips are so low, at least compared to coins, it does not make sense to use coin grading standards for chips. Would you pay any more for a MS-65 chip than for an MS-64 chip? For anyone who answered YES, I also have a slightly used bridge in Brooklyn for sale. Most coin collectors are willing to pay substantial premiums for MS-65 coins, sometimes multiples of what a MS-64 coin is worth.
Grading is nothing more than an opinion. Opinions vary from person to person. The simpler the grading standard is, the more likely it is to be accepted. For that matter IGC has not even published that their grading standards are. I for one do not care if a chip is MS-Anything. If the chip looks uncirculated, that is OK with me. I do not want to make my hobby into a business. I have better things to do with my life than to determine an exact numerical grade for a casino chip.