No They do not create glitches, because a glitch is an error in the game that the creaters do not know about. They do, however, create cheats on purpose. A cheat is a totally different thing from a glitch.
Glitches in any game are never created intentionally, all games inevitably have flaws, and eventually players discover these flaws and exploit them.
You can't create glitches. I think you didn't exactly understand what a glitch is. Glitches are false designs of the games and can be found not created.
0. Nintendo fixed all of them.
No but there's glitches.
The purpose of the Nintendo 64 was as a gaming console.
Yes
Depends on the game design and shipment
same answer as why did Nintendo create Zelda and Pokemon. to entertain and teach stradegey.
You have to make one on the Nintendo website
it can create glitches, or strange sprites if not used properly
No. Microsoft did!
Unfortunately, unless you have the same Program that Nintendo used to code the games and are able to save the data on your cartridge, you cannot fix glitches in Pokemon. The only way you can remotely do so, is to avoid the glitch all together.