Both Voyager and Enterprise share one other thing in common, they were largely run by two Paramount executives Rick Berman and Brannon Braga. Not even Manny Coto's surprising good final season of Enterprise could pull the show out of the nosedive that Berman and Braga had put it into.
Personally Enterprise failed because it got everything wrong. Wrong tone, wrong characters, wrong plots, wrong settings, wrong acting, wrong characterization, wrong logic, wrong common sense.
My personal pet peeve is episodes that just didn't make any sense. For example, there was an episode where they could have transported a crewman and an alien up to the ship, but they couldn't change the temperature in the transporter room to match the temperature on the planet so the alien would have died from the temperature change? What they don't have thermal blankets they can use? WTF? So they decide to send a shuttle down instead, but it took them something like 20 hours to adjust the shuttle so they could put the heat up high enough on the shuttle (WTF?) and the pair on the planet nearly died from dehydration while they waited (WTF?). If the transporters were working, so why didn't they transport a bottle of water down? If they couldn't do that, why didn't they send a shuttle down early, drop off some bottles of water, some food, and a tent so they could arrange a shelter? Why risk the death of the crewman and alien by doing nothing whatsoever to help them while they were waiting for a stupidly long plot device? I know the answer is "narrative" but it should still make some god-damend sense. This was endemic to first few seasons, stupidly obvious plot holes that would leave anyone with a lick of sense wondering how such amazing huge incompetents ended up running a starship*.
Actually, according to the pilot episode we know why Archer was pilot, his dad designed the ship. And the rest of the crew was hand picked by Archer. Good old nepotism. Of course that begs the question of why anyone would ever do something so stupid as put the son of the designer in charge...