I, for one, don't want bells and whistles. I want a simple grid where I can drag and drop tokens, scribble on, and chat. Audio chat and access to pregenerated maps would be nice, but not necessary.
I don't want rules systems built in. I want it system-neutral. I don't want to be bothered with setting up my VTT for 3.5, PF, 4E, 5E or whatever. What if I use custom monsters or magic items? If the rules are pre-programmed, that makes my job as GM a lot harder. I have players who use PCGen and while it's a great tool, it doesn't easily support customization.
Besides, it's supposed to be a Virtual TABLETOP. My actual tabletop does not support rulesets, does not determine damage reduction, does not link to multiple electronic devices, does not automatically apply bonuses when spells are cast, etc... It's a simple tool that lets me and my players see the same thing.
I may be the only one, but that's all I want - a simple tool that lets me and my players (in this case, players in Georgia and Alaska with whom I no longer get to play) get together and see the same things.