You have all the right to disagree. These are only opinions, Yours and mine. These opinions might be very different from Samsung's research and design decisions. I've simply stated a *possibility* for their alleged "compromise(s)". Who knows, Samsung probably decided to skip the 7420 because of low yield, and they prioritized their flagship smartphones over their tablets.
That said, liking the iPad's LCD has nothing to do with the price difference. AMOLED is still more expensive to manufacture. I would argue that OLED is generally more appealing to consumers and more pleasing to the eyes. Samsung's AMOLED has drastically improved the past couple of years. According to my own experience, people just love the "pop"... And those who prefer color accuracy are also well served by the current generation of AMOLED.
ARM tablets are no longer the mainstream "must haves". Most people don't even use them anymore. Samsung, Apple and other manufacturers are researching the needs for specific niche consumers at this point.
For those who do, I really hardly see anyone using an ARM tablet outside of social media, browsing, watching video. Maybe a magazine here and there, but nothing else. I completely disagree that tablet users who play high-end games are any sort of majority. High end, or AAA, gaming is usually exclusive for consoles and PCs. Most tablet users play less resource intensive, casual games. Besides, there aren't even that many titles (if any) in the Play Store than can saturate the Exynos 5433, let alone Apple's A8X (most tablets sold are NOT iPad Air 2s... and game developers target lower specs for iOS). The Exynos 5433 is more than capable of running titles like Asphalt 8 and Dead Trigger just fine.
Also, tablets are used a LOT less than smartphones. Therefore, one might argue that longer battery life isn't as important as thinner, lighter profiles for current tablet consumers.