no, all we want is a balance, not just new heroes each update. also the so called "fanbase" is based off idiots
There is tweaks to the balance every update as well, but the best part of an update is new, unexplored heroes and large changes.
Honestly, DotA is balanced enough to be considered a fair eSport, it's just 'cause you can't play it yourself that you're complaining. You somehow envy those who have spent too much time playing DotA.
As for Vengeful Spirit.. must say it's the first time I hear that she is so out of balance, is she too weak or too strong? I can argue against both as convincing. For instance, Venge~ is a teamhero, just like most heroes in DotA, whilst she can also take care of herself, and is suited for solo-lane early. She qualifies as a carry, so she will grow stronger by earning gold to buy items. All her spells are useful for one on one battles as well as five on five. She's a versatile assassin. Though there are weaknesses; although her Str gain is above Agility-hero average, she's not much of a survivor without an item to aid such, and as she is unable to use a dagger (because of the ultimate) she usually has to resort to Lothar's Edge, pretty much wasting an item slot because it's more of a escape tool than anything else on Venge (though it opens up some possibilities for initiations). Furthmore her attack animation is not the kindest for chasing (though far from worst), and the missile speed is not impresive either - making it less easy to control lane early.
But instead of writing a full review (in a messy manner) of Venge, why don't you tell me what makes her imba. Don't get me wrong, I'm not saying there's no imba heroes in DotA, and I'm not going to fight everything you say, I'm just pointing out that those that are out of balance, are not badly out of balance, in such a way that they ruin the gameplay if they are picked; for example:
In a -pick game, Scourge decides they want an easy win, and go ahead and pick Necromancer, Death Prophet, Undying, Axe and another, fitting hero (say Lycan), a decent Sentinel team would not give up, and although the chances are slightly in favour of Scourge (currently), Sentinel might win if they play well. That is the essence of DotA. If your team plays better than the other, and your hero picks and builds aren't carelessly put together for fun, there's a very good chance you'll win.