They think it's awesome because it's "Final Fantasy 7, man!". That's why. The same reason the "Advent Children" movie did so well despite not having a plot at all, explaining nothing, and giving nobody really any screen time except Cloud.
I played Dirge of Cerberus as well. I got fed up with the whole "linear" nature of the game, to be honest. Why did that irritate me? Several times, I got lost in a LINEAR area! I had a hard time trying to figure out where I was meant to be going or what I was meant to be doing. Also, the bosses I did encounter were lackluster and easily defeated by circle strafing and spamming the "fire gun" button.
At no point does the game even become a challenge! I ended up turning it off long before I finished the game because it was just so boring and poorly designed... I mean, there are much better shooters on the market, even at the time the game was released. Heck, there was Final Fantasy 7 if you only wanted to play the game for the Final Fantasy fix.
Oh, and side objectives in that game pissed me off to no end. I didn't know they existed until it told me I managed to fail one. So, I opened up my menu and looked at them. One of the early ones I think was saving people from being executed or dying in fires or some such. I was like, "okay, seems easy enough". No, it's not. In the very first level, they expect you to have the twitch reflexes of a coked up eight year old, as well as know the location of absolutely every single one of these people to save.
Here's how you design a game with "side objectives". Make your side objectives able to be completed on the first run through of the game. Add challenge to them if you like (actual challenge, not fake difficulty like you need to have super reflexes or the map memorized before you ever play it), but make sure that a new player has a good opportunity to complete them on the first playthrough. Now, if your game allows you to come back to previous levels with better gear, you should use this to make the challenges more easily completed instead of just plain old completed. This translates back to the whole "side objectives should be able to be completed on the first run through of the level". As such, a return to the level to pick up a side objective you missed should not be necessary, but should make the objective easier to complete. If you make it absolutely necessary to get further into the game in order to even get decent equipment or abilities that allow you to do previous challenges... Well, you've just forced your players to grind out for equipment and then grind through your level at least a second time for the objective.
I gotta admit: I'm one of the dweebs who loved Advent Children despite it being a terrible, terrible excuse for a film. It was beautifully animated, the voice acting was excellent (at least in the Japanese version. The English was good, but there's that whole "dull surprise" problem in a few places due to the Japanese cast being kinda over the top sometimes). I didn't care that the plot was confusing. Alright, I didn't care that the plot was more or less completely non-existent. I DID mind the lack of screentime for everyone who wasn't Cloud, but I dealt with it. I was too busy slobering over the animation to really pay attention to much else.
That said, I didn't have to
playp Advent Children. I have to actually pick up a controller and play DoC.
I've gotten lost too! Twice now, and I'm only four levels into the damn thing. I swear, it would actually be EASIER to navigate if the stages were open, instead of so cramped. The map is more or less useless, because there are so many waist-high fences and other f***ery to deal with. I tolerated it in the first stage, because yanno, first stage. But dudes. Once we got out of Kalm, the maps seriously needed to open up. I swear, I wouldn't mind everything else about this game if it would just let me EXPLORE the scenery it keeps taunting me with. Granted, a huge part of why I started playing was the chance to see FFVII's world rendered on better hardware. I'm a big lover of scenery and will tolerate nigh on anything if your game is pretty enough. As a testament to this, I played through and enjoyed all of
Alice: Madness Returns despite how utterly terrible that game is as well.
Even on hard mode, DoC is nearly impossible to die in. The enemies can aim, but they do it so slowly that you're in no danger whatsoever if you have any idea where your jump button is. The ONLY danger comes from the aforementioned camouflage problem. This means that the already criminally boring levels are EVEN MORE BORING.
Even the bosses are terrible. Terrible, terrible.
I actually really like the side objectives and haven't yet found any of them particularly difficult to win. Granted, I play a lot of Touhou Project, and therefore I actually do have the twitch reflexes of a coked up eight-year-old. XD