Why can't i get both?

[capnpop]

http://www.worldofwarcraft.com/info/classes/warlock/talents.html?0500100000000000000002050030133250100501300505000010000000000000

I missed burst damage with my demon spec, sure i could plow through mobs like nobody's business (2 curses and let the felguard do the rest of the work) but the inability to get off a simple shadow bolt between them beating on me...in retrospect...I prolly won't even use this spec...but I want something with the survivability of demon with the big numbers of Destruction...

i doubt I'll be able to do that