When it comes to cheating I really could care less about whether it's good or bad in singleplayer games and cooperative games, but when's there's a competitive/versus aspect to a game and you aren't just messing around with friends, instead you're legitimately giving yourself an unfair advantage over your enemies through exploits or hacks, I really think it ruins the experience. Now, back to singleplayer games, using cheatcodes was something I did in almost every game I played when I was a kid; I was really bad at completing objectives in games that weren't given to me on the screen or in a notebook and, in general, I was very impatient and it didn't take long for me to be more interested in messing around than playing the game. The same applies nowadays, but really I get tired of cheats in singleplayer games very quickly so I don't even bother 90% of the time. Occasionally, in RPG games, I will cheat and not just in a "messing around" way, and it's basically limited to Bethesda RPGs (they have so many bugs and there are so many little things you can do to make the game a bit less tedious with console commands) and Pokemon games on emulators. Pokemon games have all kinds of event-exclusive items and Pokemon that are super hard to get for no reason (Feebas in Gen 3, that is all) in the earlier generations so I personally thought it was justified. Now, there is one time that cheating just completely changed a game for the better and that was save editing in the original Borderlands (after the 1.2 patch, btw, if there are any fellow "modders" here). I could write an entire novel about all the stupid(ly awesome) guns that I made and what every single one of them did and how the parts I put on the game made them do what they did. I knew the gun statistics and parts system inside and out and I'm actually kind of proud writing about it now.
_________________
Nosce te ipsum - Know thyself