Having been an engineer at Symantec for 5 1/2 years, I can tell you that what they suffer from is the inability to build new products themselves, or a management team that refuses to try (you choose).
It's a company of "buy everything you can see, who cares if you can integrate it". Very little in the way of shared components, every product looks and works different, very little interoperability, etc.
It seemed like we always bought the worst codebases we could find, then tried to fix it. It's not due to a lack of good engineering talent - there is plenty at the company.
While I think JWT is a nice guy, one only needs to look at the purchase of Veritas to find a completely failed business model, and a CEO who doesn't seem to "get it". Even after that, they continued (and still continue) to snatch up other companies with little regard to how it will really affect shareholders. Nice guys don't make CEOs.
When John Schwarz left to take the CEO spot at Business Objects and we kept Gary Bloom (CEO, Veritas) - I knew we were in trouble.