ok so....*cracks neck and ties headband on head that reads "TOKUSATSU FAN"* I think i might as well just jump in here for a moment and don't worry I will be respectful about this. I too dislike the series and I am going to give you my little points on why:
A. Sailor Venus. Oh why oh why did they have to do that to her character. It's as if they had a choice between doing the super mysterious and serious version of Minako from the start of Sailor Moon and the goofy, silly Minako from later on in the franchise and decided to choose to do the former.....but add the fact that she's a jerk to it. Yes it's something different but to me it felt very...much a betrayal of the character. It was really not needed as they could always use Rei for any cold acting character moments but instead chose a character who is often very popular with fans for the very fact that she is so sunny and likable.
B. Darkury. Ok so *ducks thrown veggies* HEY HEY HOLD ON!!!!..let me just...talk. I know some people really love this version of the character and the arc but to be honest, to me when I watched this arc, what it told me was that they really had no idea what to do with Sailor Mercury. They could not think of a way for her to take part in things as a hero, so they turned her evil to give her some dynamics as a character, though to be honest, that always was a problem with merc- *ducks thrown veggies again* HEY IT'S CALLED HAVING AN OPINON!!!...ok so....yes it was something different for her but when the only way you can think to use a hero character to turn them evil, it tells me you didn't have a lot of ideas for them in the first place.
C. Sailor Luna. Moving on.
D. Tokusatsu. Ok so why was it a bad Tokusatsu series? Honestly it committed the greatest sin that any Toku series could: it was completely and utterly mediocre. There was nothing special about it. The fights were bland, the scripts were eh, the monster costumes were cheap (for obvious reasons) and the final twist, while really shocking, did nothing knew for a Tokusatsu series itself. As any fan of the Metal Hero franchise can tell you, a mediocre toku series can be the death knell. It did not help it's case that it was simply a third wheel Toku series at the time and thus was not given a very big budget to start off with (see the Kikaider series for another example of what happens when a series is run at the same time as a much bigger and more popular Tokusatsu series. It's not pretty sadly). This I think IMO is what rang a bit of the death knell for PGSM. It just was another toku series that happened to be an adaptation of sailor moon and not a particularly special one.
*Whew* that was a bit of a long post for me. Now if you guys excuse me, I'm going to re-watch Kamen Rider V3 and totally try and convince myself that Sailor Moon based the "Sailor Moon Body Attack" off of "V3 Body Attack".