Downfall of BlackBerry

BlackBerry once a premium mobile brand and now struggling for survival. I think, largely it has been impacted by the below factors:

1. Touch screen revolution - Around 2004-05, the touch screen phenomena started hitting the mobile market. Chinese cheap replica of branded phones with touch features started hitting the market. Youth loved it as it costed just 30% of the branded phone's cost and looked good too. Most of the big mobile manufacturer did not see this gaining popularity as opportunity. Even Nokia was guilty of it. It was Sony Ericsson with 'P' series symbian phone [starting P800] that made an attempt, followed by low end Samsung phones. Then came the iPhone around 2007 and took the market by storm & created/dominated a touch screen league. By 2010, BlackBerry started loosing share and touch screen phones became the first choice for customers.
2. Telecom penetration & Arrival of Dual SIM - Telecom boom also contributed to BlackBerry's single SIM phone demand. As people started possessing personal and office mobile numbers, single SIM phones started becoming redundant. Nokia, BlackBerry, Motorola, Sony Ericsson etc were badly hit. Samsung however sailed through along withChinese and local players like Micromax, Maxx and Karbon. In 2011, branded smartphones with dual SIM options arrived and went for a kill.
3. Competition matching enterprise level email security- Almost all operating systems by 2009 were equipped with decent enterprise level email secuity systems. IT had very less hesitation to allow employees to access office email on Non-BB phones. Nokia's MFE, iOS base email app, Android's NitroDesk etc all challenged Blackberry. BB was now lossing its hook on software and because of its brick style design.
4. Whatsapp killed the BlackBerry hook called BBM - With BBM, BB once managed to create a community and it wans't easy for users to switch to another brand. However, there came Whatsapp for free and took this advantage from BB. Whatsapp an OS agnostic app connected people with just mobiles nos. It allowed people to create groups, share images, videos etc. BBM was become a passe.
5. Fancy OS - Android and iOS - Who wants to see an ugly looking bland BB screen againt fancy iOS/Android OS. 
6. Pricing - BB realised it very late that they need an entry level phone for growth. They were some what success in doing so but it hurted their positioning. Once a brand for executives was in the hands of collegiate. It was no more exclusive. People moved to iPhone during this time which was expensive and exclusive.

 What do you think? Are are there more reasons?