Many people complain about SharePoint personally I haven't had much of a problem with it in the past until now. The theory of SharePoint is sound, it's a good idea and I was an early SharePoint Developer back in the days of version 1.
The main problem with SharePoint I find these days, is actually getting teams to use it. I have worked with a lot of companies in the past and many have it installed. However there appears to be a key issue in SharePoint which makes it harder for people to use and I've seen it on several sites.
How can I easily copy my documents up to SharePoint?
Any SharePoint dev or person who has used it will say "Oh just click on the explorer view". The explorer view is great for getting documents into SharePoint provided it actually works. You can also map a network place to a folder in SharePoint, however this also suffers exactly the same problem. It doesn't always work!
Visit the Microsoft forum's and its full of people asking the same questions who are being presented with all kinds of work arounds. From ensuring certain services are turned on, to adding SharePoint to your trusted sites right down to wiping all of your browsing history. For some this works but for quite a lot this just doesn't work. For the end user this is frustrating, they may not be very technical and it takes time out of their day. The main question on their minds is "Why can't it just work?". These users who experience these issues usually raise the problem with their tech support desk who find themselves in a difficult predicament. What usually happens is people come up with their own solutions to problems and some of them involved bypassing SharePoint and just placing the final document in there while they make use of tools such as DropBox, SkyDrive (the irony) or Email to share documents.
Get it right
Surely Microsoft understands that this is such a vital part in getting people to use SharePoint. They need to get this bit right and it should just work with no questions asked. The result of this not working is one (not all) of the reasons I hear people saying so many unfavourable things about SharePoint. Microsoft if you get this bit right you're going to see some happier people.
I am awaiting the next version of Office 365 & SharePoint with interest, if this issue is addressed here it will be a huge leap forward.