Gundam X's situation is a particularly well known one. Released during a time where new Gundam series were being released one right after the other one (even shown on the previews for next episode) causing people to eventually get a bit sick of Tomino's biggest project, this show ended being the biggest victim in this Gundam "wave".
Contrary to other entries on the series, Gundam X gives a bigger focus on world exploration and the daily life of people living on a post-apocalyptic Earth, heavily hit by colonies dropping on it, as opposed of other Gundam entries focusing only on the war segments. This of course might turn off many fans since the "war element" has always being the main focus, however Gundam X's take on the series is still an interesting and entertaining one, showing different takes on humanity's attempt on survival as mecha scavenging and creation of cults just to keep their sanity. Seeing the main character (Garrod Ran) not being a new-type archetype is also refreshing, and while Heero Yui (the main protagonist of the previous Gundam Wing) might also fit in this category, Garrod doesn't suffer of plot armor or similar things. And this leaves to the main charm of the series: its human development. Each character feels more "real" and not exaggerated as many anime series, and almost all of them have their own backstories and dedicated scenes/episodes making the viewer care more about them, and not feeling they are disposable.
Gundam X is a really fine show, with some nice mecha designs (see GX and Bertigo), however, its cancellation lead to a really rushed final arc which might leave some people with a sour taste in their mouths. Regardless, this is a show worth watching.