CPU power has nothing to do with it. iWorks was run on less powerful CPUs than A7 in the past. It's the tablet limitations. Touch interface is good for "consumption" not so much for "creation".
This is such an old line that is proven false day in and day out by people who have found that they can quite effectively use the iPad for "creation" and not just "consumption". Just because you say it's so, doesn't make it so...
Just think of the power difference between an iPhone and a Mac Pro. Lobotomizing iWork so it has the same features on all Apple platforms is like Raul Castro declaring that all cars in Cuba must have their engines replaced with 4-cylinder engines so that parts can be compatible across every car in the country. Who would blame existing BMW owners for being upset?
This is a terrible analogy. While it's certainly true that there is a broad range of difference between the power between an iOS device and a Mac Pro, but iWork is not the engine, it's more like the stereo. And standardizing the stereo across models isn't that big a deal.
As for how much power is needed for iWork, I have iWork '09 installed on an old PowerMac G4, which, according to GeekBench (in so far as such scores can be compared), has half the computing power of my iPad 2. So, while there is certainly a question of building the proper UI for the touch interface, it seems that the current and recent generations of iOS devices shouldn't have any real problem supporting the same feature set as iWork '09 has.
I suspect and hope that these features fell through the cracks as the programs were being rebuilt, and that they will be returning. The pattern has come up many times before, the Mac community seems to have a short memory about such things. One of the recent instances, and certainly one of the highest profile instances, was FCPX, but it certainly wasn't the only instance.
The original release of iWork, itself, represented such an instance. There were many features that were not in the original version of iWork that were present in AppleWorks (formerly Claris Works), and many people declared that this was a betrayal by Apple and that we'd never see those features because Apple doesn't listen, etc., etc. Well, most of those features were folded back in (granted, one of the big ones that has yet to make a proper appearance is that of a database, but you can't win them all...).
Another example is iMovie. When they introduced the "rebuilt from the ground up" version, there were many people who were unhappy because there were some features that weren't in the new version that had been in the old version. Again, there were people who said that this was it, we'd never see those features again, Apple never listens to customers and only does just what Apple wants, etc., etc. But, again, the features did make it back. As someone who got very frustrated with iMovie in the old days, and had days of work lost when a project got corrupted after iMovie crashed, I was delighted with the upgrade, even if it didn't have all the features.
Now, I haven't yet upgraded iWork. There are a couple of reasons for that. For one, my iPad is still running iOS 6, and I'd have to give up my current configuration to upgrade to iOS 7. Second, I haven't taken to time to upgrade my MBP to OS 10.9. When I saw the keynote and heard that the new versions were completely cross platform compatible, my immediate thought was that might just be the carrot that would convince me to upgrade my iPad to iOS 7.
I do a lot of work in iWork, and having that cross compatibility would be very valuable to me. As things stand right now, I am careful with what documents I open on my iPad, just to ensure that I don't open one that my iPad can't handle. To me, the older version of iWork on the iPad was really iWork lite, and I was very pleased to hear about the new versions.
All of that said, I'm now thinking I may wait to give Apple the chance to release a patch or two, and get things straightened out a bit.
So, you see, I'm certainly not defending Apple for having done this, but I am trying to suggest that it doesn't mean that the sky is falling. (I'm neither in the camp of "it's no big deal", nor am I in the camp of "this is the worst thing ever!")