Honestly, I don't fully understand the complaints of everyone so far. Not in that I don't agree with them, but those people that think CiV is bad game or whatnot. It's just following the (due to the lack of points) establishing pattern of the series.
So far, with the civilization series, all the odd numbered games are... Poor by comparison to the previous (Doesn't quite work with the first game due to lack of a previous game). However, what they did have were new ideas and such to work with, which the even-numbered games refined and made great (usually with something else added).
For example from the first game, the whole system of everything was new, but especially combat was problematic. You had attack and defense stats, yes, but then there was the random number generator, which is really necessary, that decided combat, but due to the variation on it, you could quite literally have a fighter (aircraft) defeated by a phalanx (Spearman; one defense up from warrior). I personally had it happen myself. Then you go to Civilization 2, and they refined the combat system to make it work, by adding health, and firepower (Firepower being the amount of damage they did when they won an attack/defense roll).
Civilization 3 - It added quite a bit, but people as a general rule thought it was a terrible game (I personally rather liked it because of what all it added). It was the first game with experience other than "regular" and "veteran", the ability to draft units, great people (then only a great general; with expansion great scientist), strategic resources, culture (and civilization borders), unit withdrawl... Really quite a lot. Then you move on to Civilization 4... And it refines all of those features and it does wonderfully well! (Better because of FfH, but that's not the point; there was a fantasy mod for Civ 3 as well, it just wasn't as good.) Now, they removed one feature I liked: armies, but that doesn't really matter.
So, while CiV might not be that great by the standards of Civ 4 (Personally I rather like it, like I did with Civ 3; it's not perfect, but all the stuff that they added is really nice), based on the pattern of the series so far, it gives very good hope for Civilization 6.