Don't forget that we saw the puddle all life on earth originated from during All Good Things... Although, I'd blame it perhaps more on fallout from the Eugenics War. Making perfect humans for a ruling class of SUPERMEN (Augments? Where they really afraid that DC Comics (Warner Brothers) would sue? Pussies.) is nice but they would have introduced all sorts of weird shit into their soldiers, servants and athletes to make them perfect at their proscribed profession in service tot he Supermen.
Time Travel reset buttons are a 'time honored' Star Trek tradition. Personally I think it's a form of lazy writing by the writers on how to explore character development outside of Trek dogma and to stay consistent with the established time lines. In Voyager the only Episode IMHO it was done well was Shattered only because the characters mock their own idiosyncrasies so well throughout the series in that one episode. DS9 IMHO did the best of any of the shows with such memorable episodes as Little Green Men and Trials and Tribulations Enterprise was the worst with alien Nazi's in Storm Front parts I and II. The sad part of both those episodes is the series didn't even try to mock itself with the absurdity of the plot.
To be fair on Enterprise the captain was a moron. It's nineteen 46 the war is raging on and there are Nazi's in the White House but he can't tell the freedomfighterlady that he's from the future because and I quote "I can't alter the time line". He's an idiot. Thank god, that Cylon from VOY In the Flesh as evidence tot he contrary withstanding, no one will breed with him. They had to send a shuttle mission to the surface to tell the difference between earth 1946 and earth 2154. MORONS! Voyager's crew made bad but logically plausible decisions from time to time, but the Enterprise crew were a gold medal winning squad of imbeciles week in and week out. For gods sake, every time that Daniels guy turned up, there was reels of evidence that he was a dick working for evil but Archer trusted him implicitly for the most part.
Time Travel is just a time honored tradition of sci-fi in general, H.G. Wells anyone? However, I wish time travel were possable because someone needs to send Bill O'Rielly back the 1800 where he belongs.
The easiest solution is to nab him from the street in an unmarked van, drug him up real good, slap a white hood on him, spin him around a few times and set him off to wander aimlessly around Detroit..... it won't take too long for him to disappear. (I'm not being serious, nor am I promoting kidnapping )
Come on. Of all the sci-fi on film and TV Trek used the genre [over used it if you ask me] the most. Star Wars didn't touch time travel at all. BSG didn't touch time travel at all. Babolyn 5 tangentially touched it. But in Trek not only is time travel prevalent and frequent you have varying methods apparently and difficulties for it to be used. In the film Star Trek IV McCoy and Spock make it sound simple. And of course warping around the sun is quickly forgotten. In DS9 we have the prophets who are able to manipulate time. And of course in Voyager who's writers were addicted to it: Parallax, Time & Again, Eye of the Needle, Death Wish Futures End parts I and II, Before and After, Timeless, Relativity, Fury, Shattered, and of course Year of Hell parts I and II
There's way more sci-fi out there than just Star Wars, Trek & BSG. Quantum Leap, Outer Limits, Twilight Zone, Back To the Future, Flash Forward, HEROES, Eureka, LOST, Life on Mars.... All used time travel elements. Heck, even "A Christmas Carol" uses it.
Charles Dickens once helped Doctor Who defeat an Alien Zombie Invasion on Christmas Eve. Now, that was good telly.
As others said earlier, Annorax's weapon doesn't make too much sense. I think of it as kind of a "hack the Matrix" gun, and that the timelines resulting in it's use will be a little "glitchy". It's the only way I can see it not working it's way back erasing everything all the way back to the big bang. Star Trek has always been a big believer in "destiny" - Tuvok and Kes/Seven enacted the same scene in "Before and After" and "Year of Hell". The mirror universe usually has the same people on the same ships as the prime universe at the same time despite massive differences in curcumstances (and weird disruptive stuff like 22nd century humans getting hold of a 23rd century starship), Kirk and co united on the Enterprise in STXI amidst all sorts of unlikely coincidences, Archer still founded the Federation after a couple of huge timeline alterations costing millions of lives...and so on. So, Annorax may well (re-)build his weapon one day, or maybe even someone else will do it in his place. Or not .