1 - Crystal Maiden. Nukes are nothing special, aura even as global loses it's effectiveness after early game, ulti is easily counterable, unwieldy and unreliable. Poor animation design. She's made of suck. Yes, I've heard of animation cancelling.
2 - Bounty Hunter. His dominance relies on getting farmed up, and even then he isn't that much of a carry. His farming relies on herokills, and to get them he relies on his invis and overconfident soloers. In hero design you can't rely on noobs, and invis is easily countered.
3 - Clinkz. ^
4 - Techies. Good Techies is good, but having played him a couple of times, I've found the shocking news, that when a ranged hero gets a gem, he becomes fucking useless.
5 - Phantom AssAssin. To make her useful, you need to stack damage. With low hp like that, even 30% dodge doesn't help you against a bit of focus fire and/or nukes. Even when farmed up, she's not all that big of a deal.
6 - Rigwarl, Bristleback. He bases on stacking effects. Stacking Quill spray allows him to do massive damage early, but the damage becomes ineffective, not only because of increasing hp of enemies, but because the damage is reduced by increasing armor. After 30min it's hardly worth of using for any other reason than Warpath.
His abilities don't compliment each other. He is supposed to be an offencive tank, but he has low str gain(2.2/lvl) and bristleback(skill) works only when running away. Also Goo as a chasing ability is frustrating, as the hero briefly stops when you cast it.
7 - Venomancer. He does nothing that someone else couldn't do better. Hell, even Viper alone can do everything he does better. The damage of Nova is highly unimpressive and becomes nonmentionable with high hp, high regen, Hood of Defiance or even Lifesteal. Wards are good early -> early midgame farming, but after that wards are not even worth of using for anything else than temporary warding when pushing.
He is a decent farmer with some ganking abilities, but he has nothing to do with it lategame, no role, no steroid, nothing.
8 - Bloodseeker. Another nondisable agi carry. Just a bad one. He relies on opposing bad opponents for herofarming. Baaaaad starting point for a hero.
9 - Spirit Breaker. His style is to throw himself in and hope for the best. Works when opponents are unskilled enough to not sense danger, unorganized enough to not stick together and when your team is dominating enough for opponents to be weak enough to be pwned by charge.
In a groupfight, he is the first one to die if he even bothers to attend.
10 - Nerubian Wiener. He just is weak. No nukes, bad built-in orb, low hp, low statgain. Time lapse is a neat trick, but it's a trick, and tricks can be countered. Silence and gg, stun and gg, nuke and gg, anti invis and gg, armor reduce and gg, it's just gg. Watchers are sex though, and that's all he is worth most of the time.