WotC has done a lot with the character builder, and there is a ton of varied content presented in Dungeon and Dragon magazines, appealing to all sorts of interests among the 4e players. These are important pieces of the DDI, so making such a sweeping statement of neglect on the part of WotC is unfair.
And the Compendium! The Compendium is the best thing since sliced bread and canned beer.
I think WotC was behind the curve from the start with the VTT. There are tons of good VTT's available at prices ranging from reasonable to free. I had tried three different VTT's and looked at one or two others back when 4E launched. I think the market for VTT's in general is pretty small, and I don't think the product WotC was offering could compete.