The problem with holding technology stocks is that you don't know if the company will survive in 10 years time or not. With the rapid pace of change, companies that may rule the world haven't even been invented yet.
For example, tablets are here to stay, but who will be profitable making them 10 years from now?
I can, however, be reasonably sure that Coca Cola will still be in business 10, 20, even probably 50 years from now (and profitable and pay dividends).
Since I live in Canada, Canadians all know the story about Nortel Networks which was a 100+ year old company that got decimated and its stock down to zero.
Another example. 8 years ago, virtually everyone was doing the "crackberry prayer" and no respectable adminstrator would allow the highly unsecure and toy like Apple products onto the network. Today, Blackberry is on the ropes and survival is questionale.