I'm no suunto fan, but I just wanted to jump in and say that I don't think this is really a problem specific to suunto computers. Rubber watch bands degrade over time and break without warning. I've had the same thing happen with two Scubapro computers. It's just a fact of life with rubber watch bands.
As you've noticed, you can opt to use something other than a rubber watch band. In addition to going with that nato band, you could probably find bands that fit which are made of various metals (even gold, if you want to pay). Many folks swap their dive computer straps for bungee cords. Those last a long time and are easier to don/doff since all you do is stretch it out until your hand fits in it.
Well.. I guess I should back up a little. It IS suunto's fault they elected to sell a computer with a rubber band, but that's very common. They could have sold the computer with a metal watch band (some suunto computers come with metal bands I think). They could have sold a computer with bungee or nato straps, too. Those all have drawbacks that I'm sure suunto wanted to avoid (high cost with metal bands, less aesthetically pleasing with bungee).