Tryndamere is free to disagree... he has an opinion. I have a differing opinion. That doesn't mean that either of us are any better or any worse of a person for disagreeing. Simple as that, really.
Would be curious as to why he thinks that way though:
1) Twilight Shroud's +Armor effect is rather pointless, as what armor really helps mitigate (damage from auto attacks) the stealth effect does better, anyways.
2) Twilight Shroud is an outlined AoE where the character is stealthed in. All one simply needs to do is AoE the area, and Akali takes piles of damage, with no real way to get out other than to leave the outlined area, and become visible again. For every other character with a stealth mechanic, they need to get either vision wards or an oracle elixir to counter effectively. For Akali, all that is needed is an AoE (especially as she has the bonus +Armor, and not the +Magic Resist)
3) Every other character with a stealth mechanic doesn't have this rather unique problem. I can only surmise (and again, this is just my understanding of it) that Twilight Shroud is meant to dart in and out an area, attacking everyone, while being harder to hit. (Thematically speaking, like the Nightcrawler sequence in the opening scene of X Men 2). This is why the area is outlined (as in, this is the area you don't want to be in)
The problem with is that any targeted ability that you aim at kat and click, even if Akali goes back into stealth by the time the actual ability is cast, triggers (Kat's Shunpo, Kat's Bouncing Blade, Garen's Execute, Nunu's Snowball, etc). So its effectiveness in game seems to be drastically less than on paper (where it sounds awesome, quite frankly).
Twilight Shroud, in my experience, isn't nearly as effective in a team fight as it sounds. Combine this with the lack of an actual effective escape mechanic, and Akali, while themically cool, just seems a bit underwhelming, and not a character that, if I were making a team, would want her on.