Totally agree.
Cheats take away from any feeling of progression and accomplishment.
Earning money by doing various missions, activities, gambling or by robbing is better than just entering a cheat. Progressing through the Main Story missions or completing a certain number of challenges/ activities to unlock weapons/ upgrades/ cars/ safehouses is better then entering a cheat. Looking for collectibles and getting spawned weapons that way, or completing vigilante/ ambulance/ firefighting missions and getting bonuses boosting health/ armour and the ability to become fireproof is better then just entering a cheat to become invincible/ or replace your health and armour automatically.
Cheats are better for going on killing sprees, and for generally creating as much mayhem as you can, seeing how long you can last against the cops ( although if there is an invincible cheat you could last forever/ unless they have a glitch like in GTA SA where police helicopter rounds are able to penetrate you ). I don't save after accessing cheats, and usually won't fuck around with them until most of the game is completed. And I definitely never use them for story missions.
I agree with this 100%. The only time I use cheats is after I have already beaten the game legit, and sometimes, not even on my second, but my third run-through, I would then start using cheats. Only because after a couple of run-throughs, I do get tired of starting off with nothing and having to work it all back up again, so I'll do the money, guns, and cars cheats. I'm not a fan of running through the streets, free roaming, causing mayhem after I beat the game, it gets boring to me; I like to just start it back up again.
Hopefully, one day GTA will have New Game+.