Depends how you hold the phone I suppose. I've never found that to be an issue the way I hold it. I'm more annoyed by the new 4.X menu buttons that always in the upper right side of apps. I add menu back as always on and usable softkey on my GNex just cause of that. Suppose if you can't do that you start biasing your hold higher??
Hah, at the end of the day I would prefer something that will never happen in a 4 softnav bezel button device that includes an always usable menu key.
The rom I'm running puts the menu app in the bottom right for most apps. It is a bit annoying there, but still usable I suppose. I should work on customizing it more though.
However regardless of that, I have a galaxy nexus, it is exactly as wide as the moto razr hd, and is just a few mm taller and maybe a fraction of a mm thinner. Despite that, if I try to touch the bottom areas where there would be soft keys, I find it hard. The keys need to be on the screen just that bit above the bottom. There is no other way to hold the phone. One handed, as a man with above average sized hands, I can't reach the bottom right of the phone where you think these soft buttons would be great, without holding the phone in a way that makes me feel like a slight gust or knock could very easily cause it to tip out of my hand and drop. Holding the phone the way I hold every phone, with the aim to be able to reach the entire screen with my thumb, I can just reach the screen. reaching below it to the bottom of the device requires sliding the device higher and into a precarious grip.
Admittedly I can stretch and reach the bottom of the phone, holding it just low enough to reach the bottom while holding it well, but this makes my unable to reach the notification bar which I pull down fairly often. Plus since most people have smaller hands than me, I can totally understand motorola sticking to soft keys at that size. I'm not saying it pleases everyone, but that I think a lot of users would prefer it to having keys lower down.