I personally don't see a direct issue with 18/1/1 or other variant builds.
However, as with
@Svirfneblin I do agree that given how SSG devs have previously gone with the mantra that "hard choices" should be made (including in character design choices), in far too many cases, the current Capstones are a far cry from being a "hard choice" when compared with going with other class splits, even as little as 1 level of something else just for the low hanging fruit there. So there is clearly something lacking with the Capstones as they are now.
Most Capstones are just +2 Dual Stat, or +4 Single Stat, and a little something else. But more often than not that extra little something else barely stands out in the world that is available for character design now in DDO. Especially once you factor in gear from Epics and onwards where it basically makes having a Capstone a moot point in many cases.
Whilst many forumers might be seeing the attack on the 18/1/1 split and it's variants, you cannot deny that many Capstones are not performing as they should; acting as something that is viable to aim for rather than go with a split that gives as much benefit or even more to your build. Rather than simply being a pat on the head for staying single class.
Adjustments to Capstones are definitely needed.
J1NG