Eh GoW III wasn't that great the first two are the best in story, puzzles, and level design, II improved the gameplay while the story suffered, but it gained more than it lost.  GoW III had some combat improvements that really just made combat more flashy.

The first two God of Wars I give credit where credit is due, it brought action games the the fluidity of the days of 2D action games that disappeared when  action games went 3D, DMC was a big step in this but GoW did a little more and made an impact in the development community so others would follow suit.

However II improved much more while III was about the eye candy, way less secrets made into the stages, more focus on the kills, and it was shorter but boy do you see those pores on Kratos lol 

The reason Kratos locks what you can do with him is how he's built as a character, do you see a Kratos platformer? Do you see a new GoW game with Kratos with much less focus being the brutal melee action and a high focus on magic making him essentially a mage?  No he's pretty set in what they want the character to do, he was a purposely made character and was never intended to be versatile, just a brutal action star.

As for CoD they changed a lot between 1, 2, and 4 Modern Warfare (CoD3 was just a rushed product and a blemish, though that is proof of people will cry foul if you fuck things up) since MW I agree it's been a lot about tweaks, but in a multiplayer focused game rather than single tweaks mean a lot more, what people want from single player experiences and changes in the game are like Mario 64 to Sunshine to Galaxy, those were not tweaks but rather entirely new elements.  

Back to CoD, MW was a big change and made the series a lot better, World at War improved the multiplayer with the right tweaks, then MW2 had a lot of issues cause they wanted to up the scale and it became even more over the top hopefully Treyarch takes that formula and tweak it right again for multi, just hopefully they will make a singleplayer worth playing this time.

I thought GoW III was the best in the series...it wasn't just eye candy for me...it had the best boss battles in the series. That and the titan sequences were insanely awesome.

More of the same is fine with me as long as its just as awesome as GoW II...thats what I had in mind when I was getting hyped for III.

But I was surprised by its improvements...improvements that you seem to have not noticed.

For one; rideable creatures. Breathing fire on your enemies using a Cerebus and mauling your enemies with a cyclops were great fun ! Definitely not just making it flashy.

Remember that bigass Cyclops battle on one of those boxes in the Labyrinth where you could maul other cyclopses with your dude ? Or setting fire on those Minotaurs using a Cerebus ?

Those sequences were amazing.

The other thing is the items.

Hermes boots - adds a different dynamic to dodging and the air dash is a great way to start ariel combos.

The Apollo bow is pretty much Kratos' equivalent to Dante's guns....not much damage, but adding a little strategic value to the game (especially useful against those Skorpius spawns on Chaos mode)

The helios head hid some secrets, made hunting for chests a bit more challenging than normal,although it was pretty useless in combat.

Speaking of secrets, you say there were less...yes, there were less easter eggs, but there were 10 godly possessions..make of it what you will.

And I cannot stress how much the gameplay changed due to the sub weapons.

Exile - The blades we know and love...Damages quite a lot and is fast enough.

Hades Claws - Faster than the blades, but weaker...primarily used for its soul summon ability..weakest weapon in the game.

Cestus - Oh hell yes. Boxing gloves of death. Slow but powerful, these were my favourite weapons in the game (see: Avatar) Vicious Maul FTW ! 

Nemesis Whip - Extremely fast paced blades focused on air combos. L1 Square launches you to the air. Hold Triangle doesn't launch Kratos into the air, instead electrocutes air borne enemies. Drastic change from the normal weapons imo.

Overall, I thought it was God of War II on steroids.

Opinions differ I guess. Though I agree on story...on that side, GoW III could have been a little better. Puzzles...well God of War didn't exactly have the best puzzles, but GoW III had some brain teasers as well...especially Hera's Garden...though the quantity of the puzzles were less I guess.

Level design, yes..GoW had the amazing Pandora's Temple, II had various locations which made my jaw drop, and III was about the hall with the flame of Olympus and Hades I guess..I thought Hades was very well done, and the Flame of Olympus area looked almost CGI to me...lol...

I think the fanbase would be extremely pissed if they see platforming kratos or mage kratos...Kratos is kratos for the killing machine he is. He is nothing more, nothing less...I'm not denying that.

Remember what happened when Mortal Kombat lost its blood ? Yeah....don't want that to happen to God of War.

The best thing they can do is either end the franchise before it becomes the next Guitar Hero. I'd rather remember God of War for being an amazing series rather than a milked franchise that went downhill.

Alternatively, they can change the character to someone who resembles kratos, and switch to norse mythology and start over, using the God of War name if they wish to...

See I wouldn't mind them using different mythologies cause many have their own god of war and you could have a character that represents that mythology better and make him/her a character that can do more than swing around swords in bloodlust, still keeping it violent, but do things differently which would liven up the series a bit.