1. They're too tight.
2. The system is no longer original once a key component of it is replaced with a third-party connector.
3. Most of the issues with connectivity can be solved simply by applying rubbing alcohol to a game cartridge and pulling the cartridge in and out of the system repeatedly and moving it up and down. If you read any service manual for the console, it says one should be cleaning the system periodically- granted it says one needs the Nintendo brand cleaner system, but this method will work, and most people are doing goofy things like boiling the 72 pin or bending the pins, making them even less functional.
The design of the console was flawed but it was built to last. I have a system in front of me that was built between 1985 and 1990 with original capacitors, pins, etc and works fine.
It upsets me to see so many eBay listings advertising "new 72 pin." And with the HDMI mod, there will be even less consoles in their original condition.