"the aiming makes it ridiculous to try and target the tenticles"
- you tried to read my guide, and it's apparent you understood none of it
"any time you do hit them he performs the most sick cheap crap spinning around slapping you with his phalices"
- you need to learn to JUMP. Better yet, Screw Attack to completely dodge that and many other wonderful attacks. Again, already mentioned in the 'guide'.
"the screw attack is as worthless as the targeting; i only end up taking a bath in phazon"
- you know, you could cut the Screw Attack short by pressing the Jump button one less time, which is completely within your control. But you seem to not like the Phazon so much you'd rather get slapped by the phalices -- also addressed in the 'guide'.
"but in reality the boss would be easier with just about any other first person game's controls"
- let's apply Dual-Analog controls. The situation doesn't change significantly. So you can freely aim and move at the same time? Very nice. Yet you still move around at Samus's walking speed, you're still running around beneath the tentacles, he can still reach you, and you're right where he wants you. Given the proximity of the tentacles, the angle of spread amonst the tentacles are still wide enough to warrant considerable aiming time for each of them, especially when they don't all fit within your visor's view. However, on your duey-analogy scheme, you'll have to worry about aiming, moving, beam weapons, missles, and jumping for dodg-- OH WAIT, I THINK WE RAN OUT OF THUMBS. You're still in a dangerous position, you're still waiting to get slapped, and you still need a means of escaping if you wish to not get slapped (every attack is preceded by a specific shriek or sound. get. a. clue. If you DON'T want to get hit, DON'T stick around.). Even with different controls, it STILL boiled down to tactics. How do you get more tentacles/targets to fit within your view? Distance yourself. How do you effectively distance your self? Screw Attack. How do you dodge [blank] attack? Get the hell outta there. How do you effectively get the hell outta there? Screw Attack.
Master Chef's gonna have a tough time without that nifty Chozo-Lumi technology. It's not impossible... but if I can take care of that boss phase without losing more than half a bar of health, something is obviously lacking in the other school of thought.
"look at the old Metroid or Zelda on NES, very very simple, two buttons, but those games are still a challenge and the reason is you have to search and solve puzzles"
- 3D Nintendo bosses have been their own kind of puzzles since say, Mario64. Even the Boost Guardian -- he's hard because... he's hard and your life is draining the entire fight -- yeah that fight was "unfair" [only a bit] but all the design traits of a puzzly-boss are there. There are FREE windows of opportunity, and other windows you have to figure out and trigger for yourself.
You just failed to identify them.