Considering the first couple of seasons of Voyager had some of the worst Trek episodes ever, like Twisted and Threshold, I don't see how the first couple of seasons were that well written. Voyager didn't stick to its premise, that's a huge problem.
I just purchased the first 3 seasons of Voyager on DVD and had a marathon viewing of the first three seasons and I completely disagree. Sure there was a stinker or two but no worse than any other Trek series. I really enjoyed the first three seasons and there are many episodes that I will view again and again.
But see that's not Voyager's biggest problem, sure all the Trek shows have really bad episodes, that's going to happen with every TV show. Voyager's problem is it mediocre, it has more forgettable and bland episodes then the previous 3 trek shows. The truly great episodes are far and few between for Voyager compared to other series. Episodes like the Inner Light, All good Things, City on the Edge of forever won Hugo awards, no Voyager epiode has done that. Also DS9 episodes dealt with really weighty topics, like war, sacrifice, duty, honor, corruption, genocide, etc while Voyager was using technobabble to get out of anomalies
Again the problem is they ditched the premise almost from the outset, the Maquis Star fleet tension just disappeared and none of the hardships of having to make tough decisions to survive in the unknown came to pass, they still had the Holodeck for Heaven's sakes. Instead Voyager came off as TNG lite, instead of its own beast.