I’ve always liked Nemesis. Saw it on opening night and thought it was thrilling.
I saw it on opening night in a totally empty theatre, it thrilled me also.
There’s some stupidity, yes. The Kolarus III scene is ludicrous, even as an action piece (although Worf’s “Very astute” line is a franchise favorite....so there is that). I do think they left a VASTLY superior version of the film on the cutting room floor.
The Kolarus III scenes, whilst not great don't bother me as much as some folk, they were just defending themselves after all. It's the contrived nature of the plot and the fact that a dune buggy was introduced at all that bothered me. With the technology at their disposal you'd think they'd have some sort of craft that didn't require wheels. The whole thing came across as a box-tick for inserting an action scene for Stewart. Could have been executed a lot better but I can generally roll with it.
Data’s death? Doesn’t bother me in the slightest.
Me neither, I fully expected it to happen before the films release, and there's an argument for it needing to happen I think. Again, the execution was lacking - the space jump was great but the simple 'goodbye' whilst Stewart was just stood around looking like a doofus could have been done better I think, though a prolonged goodbye like TWOK would have been a bit too on the nose considering what the film had already cribbed from it at this point. Now the wine toast scene in Picard's quarters, I found to be very emotional and hit all the right notes for me, as is the wedding scene which gives me a lump in my throat every time I watch it.
Shinzon’s jumbled motives and irrational plan? The guy is completely insane...doesn’t bother me.
Jumbled motives - never got that one. The Romulans spend half the movie demanding that Shinzon attack earth for their continued support. The Scimitar may have been a badass ship but I'm sure Shinzon would still like the Romulan's fleet at his disposal moving forward.
Now the 17 hour wait whilst he needed Picard's blood,
that was just dumb and pointless.
As was failure of the Enterprise crew to simply turn the sodding lights up when the Remans board the ship when there's a scene that clearly shows their weakness is just preposterous.
Action and pew pew? I always love Action Trek.
Aside of TMP (which I love) and maybe TVH I want to see a bit of pew pew. Nemesis delivers this in spades in it's third act with the space battle and crash, which I think still looks great and is hugely exciting and entertaining in ways a Trek film hadn't been since TWOK in my view. They really nailed the same feeling of desperation and of all being lost in the same way as the 1982 classic. All deliberate of course.
With respect to
@NCC-73515 nothing about the number of decks or the displays would ever cause me to actively dislike a film...so no issues there either.
It's an error/oversight, but it's nowhere near as big an offence as the 'deck 78' from TFF which is way more noticeable. I found the Riker fight to be probably the worst scene in the movie, it was poorly shot and lacked any kind of tension, and the pit where the guy falls was lame AF.
Honestly, there are times I think it exceeds FC as being the best TNG film.
I'd agree with this statement also. Nemesis does look cheap in some places but does have some excellent FX that still hold up well today, I think it feels like a more cinematic film than FC in general, and I think the score is every bit as good too. I enjoy FC, but I like the darker, more adult feeling Nemesis more I think. FC is not without it's problems in the writing department either. I don't think there's much between the two to be honest. Insurrection is nowhere to be seen, and Generations, bar some stunning FX and cinematography isn't as good either.
Moderators, please move my post to the “Controversial Star Trek Opinions” thread if warranted.

Been on that thread myself.
To the OP though, has my opinion of it improved? No, not really. I always enjoyed this movie, and it's probably the one I rewatch the most out of the TNG outings, but make it better? I think you answered your own question in that it's nice that it's no longer the footnote of 24th century Trek, or TNG for that matter.