eh, I watch anime for the entertainment factor, if a series fails to surprise me with a at least somewhat unpredictable plot and char development and fails to deliver what I look for in a anime(also action, comedy, epic moments, emotional moments etc), then I'd consider dropping it(anime with slow development such as Xam'd: Lost Memories is definitely not my cup of tea no matter how epic the outcome might be). I'm sure I've missed a lot of hints of meanings and don't really get to look at an anime's beginning from its end's perspective but that's the trade off for my time. for me its kinda like playing RPGs lol, beating a game without playing it twice or get to the hidden dungeons and bosses. its what I miss out for getting the time to play other games. also like movies, I'd like to watch all the movies currently out, but time only allow me to either focus on a few or watch as many as possible. to me, a anime don't fail because its plotless, but because it doesn't have the action, comedy, and moments I'm looking for. I think a anime don't really need a strong plot to be good, like dragonaut(action-fan service-moments-fan service-action lol), but it helps.
think somebody once told me that you get a different feeling everytime you rewatch a anime, and you gotta watch it twice to even be able to grasp the full story and appreciated the anime. I certainly don't have the luxury for that if my goal is to find as many new things out there as possible. tho for some classic animes I'd for sure go back and rewatch sometime in the future, prably by the time I have a different view on things. I think there isn't really a "right way" to watch anime, it all differs depending on what you are looking for in it, even if its different then the creator's intend, I'm the one who is watching and I only want what I'm looking for. in other words like someone else posted here, I can't miss what I don't look for, currently

and I'm sure that'll change in a handfull of years.