Dragon Quest VII is my favorite DQ and also my favorite JRPG of all time...
There is just so much to it that I love. The island to island style is not really any different than how most other DQs play out. It's no more or less linear than the normal fashion as you don't really explore in other DQs, you pretty much go from A to B with distractions in-between. One thing the islands do brilliantly is give you much better self contained stories. With the really hefty amount you go to, I found at least half to have really interesting plots, with the other half still being pretty good. Ones like the ending of the mech island still stick with me today. As for the gameplay... it's just so damn long! You have a chunky story that can last 100 hours, plus a pretty good amount of post-game content with even more in the remakes. I also love the monster collecting and town building mini-games (I liked the town building better in the PS1 version, though). The classes... so many classes! I love mastering classes and learning new moves, of which there are hundreds. It kinda stinks in this version they remain job exclusive whereas in the PS1 they where permanent, but I can see why they did it.
In the end, it is just classic DQ action compacted into an insane amount of content. I love the story structure a lot because it's unique and gives a lot of variety. Plus it has a lot of stuff for someone who loves grinding and leveling like me.
My main confusion is for you could like the earlier DQs but not VII. You need to get your incorrect opinion fixed! (Not really, but I love the game).