You're correct, and I didn't mean to make it seem as though it was an intentional process.
But historically, when one aspect of the ecosystem goes unchecked, something usually comes along to take advantage of plentiful biomass, one notable exception being humans.
Don't forget domesticated cats. It's still a wild animal, but one that has adapted itself to live off humans in quite clever ways (essentially by mimicking human children).
Yes, except even herbivores occasionally show evidence of eating meat. Deers are occasionally seen eating birds, similar has been seen in Cows (IIRC Lal the cow was documented eating its owners chickens from the coop) and in fact all Bovid species occasionally show eating birds.
If there's a world of untapped food, this exceptionally rare behaviour would rapidly become advantageous, especially when the prey isn't adapted to the unusual predator.
Evolution has no guide, but all evidence shows it evolves into almost every available niche and quite specifically that any large available resource will be tapped.
So what if some herbivores will occasionally eat meat? You're assuming that the organism should look, act, and behave strictly within the boundaries of an English description.
Again, evolution is still unguided and to assume that something will evolve into an open niche is a gambler's fallacy.
I'm not even going to attempt to argue this, because I sense I'm simply going to be banging my head against the wall because you're going to be locked into semantics and obsessing over "unguided".
Convergent evolution, and history argue against you. C4 photosynthesis evolved independently 60 times. There's no guarantee it will, and I'm not arguing it will. However, the weight of evidence argues that if there's a readily available niche it is a matter of time.
If you argue I won't win the jackpot, you're likely right - in fact I'd put money on my probability of losing. However, if you argue no one will win the jackpot in the next 100 years you're an idiot.
You're the one trying to use the semantics of "herbivores" to make a point in biology. By assuming that there is even a "jackpot" to inevitably be won is making the gambler's fallacy. There is no "jackpot".
Quit projecting and just stop already, electromagnetic. You can't even bow out and admit you're wrong gracefully, so you skip straight to name calling.
You don't even know what the Gambler's Fallacy is! Gambler's Fallacy is betting according to a limited collection of statistics (red came up 5 times in a row, bet on black!) and not to true probability.
I didn't intend to refer to you personally as an idiot, but turing a phrase however that appears very lost on you.
I'm certain you're just intentionally being a troll, because you're unwilling to make a single basis of an argument or even support your reasoning and can't even use your terms correctly, and now you're attempting to bait me with condescension.