Why must people go into the cloud?
Why? Because the cloud provider says so. Because the Boss has heard that everyone is doing it, so they should too. Because its sooo much cheaper. And so on.......
Sorry, but it's all crap spouted by snake-oil salesmen. Yes, the cloud has its place, but handing your entire companies data to someone you don't know AND get charged for it? Would you run up to a stranger in the street and hand your company books to him/her and ask that person to look after them? Oh, and by the way, give them loads of money for their trouble?
The security of the cloud will always be an issue. A company that has everything in-house is much less of a target for hackers than, say, Microsoft's O365 or Amazon's servers.
Downtime. I build and install systems for SMB's. With one customer, for example, their data and mail servers have had less than 12 hours downtime in 6+ years (and 9 hours of that was due to a relocation). Compare that with Adobe last year - http://www.theregister.co.uk/2014/05/15/graphics_pros_left_hanging_as_adobe_creative_cloud_outage_nears_24_hours/.
The new European Data Protection Regulation. Have you read it? Before you sing the praises of cloud providers, why not ask them just how much their prices are going to have to go up by, when they (and your company) are legally forced to be compliant. Remember, if your company is processing more than 3000 records in the cloud, hiring of Data Protection Officer is mandatory (which has just added at least £30,000 to your wages bill). Plus all the new risk assessments that your company (and the cloud provider) are going to have to do to be compliant (how many man hours are going to be consumed with that one?). The cloud is about to become one very expensive place. As it is, the cost crossover between an in-house server and the cloud is around 3.5 to 4 years (where the in-house server starts to become cost-effective). I doubt that after EDPR compliance, any cloud provider (except the very largest) could compete with a in-house system from day one, let alone for 4 years. This will force may smaller cloud providers out of business, so where will your data go, if you have been using one of these?
Data links. If someone puts a jack hammer through a cable (it's happened), lightning strike, cable theft etc, you lose your broadband. Ah. Huston we have a problem. At least in-house you only lose (new) email and people unable to update their Facebook profiles.
So why should people go into the cloud?