With high creeps, anybody without a ranged AoE is going to be going back to the crystal for health fighting off creep waves. With high towers, demigods with heals/shields or have long ranged get a huge buff in power because hiding behind the tower goes from being a sound tactic to being the only tactic. It's not balanced. Even if the concept is better, which I'm not conceding, the game is balanced around the default settings.
Also, NOBODY at level 3 can chase you into towers, unless you are really, really low on health and they are really high on health, in which case you were probably styaing in your lane too long anyway or just deserve to get beat down. And knowing when to chase and when not to becomes even EASIER in high powered towers/creep games; it goes from having actual decisions to make to "wait until the towers are down or I have stacked tons of armor and health to chase."
Basically, with high creeps, it just makes the game blah because all melee DGs are out of luck and all range DGs without good AoEs are out of luck (which means Reg has to go with angelic fury since mines don't give him gold), and with high strength towers ranged DGs get an even more massive advantage, and Sedna, QoT, and Oak become god tier because they can hide behind the towers and recharge their shields.
Default settings are the best. Anything on low, and it becomes a joke (though Warscore low can make games less about rushing to giant, but then it just winds up being a longer game that ends with giant).
(and in my most recent game, I DID get an AF ring, Bulwark, Girdle of Giants, Mageslayer, Deathbringer, Orb of Veiled Storms, Cloak of Elvinkind, and Ashkandor combo. Long story short; my enemy hit level 19 before quitting, and neither of us had gotten to catas, so I just farmed for the hell of it.)