Well ...
If..."It seems to me that a computer network, with all the possible points of failure, like dns servers, active directory, etc, is more likely to go down than google or the internet." then...
The data center has every one of the failure points you mentioned and about 50 more. Now when they have a major failure (like Amazon and Microsoft cloud services have both had more than once) and your a little 5 man shop, I am sure you will be at the top of their priority list.
If your company has to comply with? HIPPA, SarbanesOxley, or a ton of other regulations you will certainly have problems with Google doing your hosting (at least if you want to comply with regulations). But hey, maybe your small company doesn't have to worry about that.
Have you ever actually read the terms of service on some cloud services? Many of them have the rights to parse your data, others even go so far as to claim ownership of your data. But I am certain that your data is not that important to you in the information age.
Oh, and most people don't think about it, but guess who is responsible for backups? (Hint, it normally isn't the hosting company).
What happens to your data if you miss a payment or two? It just goes poof in a cloud (pun intended) of smoke, and your out 5 years worth of data. Most small young companies can never recover from that.
Yeah, that is just exactly what a young upstart needs. Role the dice if you want to...
The smart money will hire an IT Professional to choose, setup and maintain the proper solution for your specific situation.
The idiot with a pen may sign up for some cheap cloud service, but that is most often not the cheapest long term solution, nor is it the most stable solution.
