I'm through hating on the show because enough of the criticism has seeped into the general public awareness, which was my objective in ranting about it in the first place.
To be frank, I only cared because the VN was getting critical praise for "quality of research" and "intelligent writing". Steins is neither, it's a thriller with anime stereotypes and little character depth. Stereotypes/depth isn't a big deal with thrillers (Die Hard?), but it doesn't belong in the conversation of comparison with a thinking man's story.
It's like how TLC likes to troll me by saying The Avengers is better than Citizen Kane. They're not comparable except that they're movies.
If all else are awesome, it does not matter.
What about Fridge Logic?
That said, you're generally right, but Steins violates its own rules to make the stupid ending happen. Japanese endings are supposed to be sad/tragic/statements of transience, so throwing out the world logic to make a 'happy' ending is bunk.