Don't listen to these people...
Use presets if you want, I -know- FM, RM and Subtractive synthesis like the back of my hand but do I put it to use? rarely..
I ain't got time to sit there and faff around with creating patches.. Are people going to care if you have a rhodes in your track what sounds pretty standard? Not really.. Are people going to moan cause you're using a super saw pad? No sir-y.
Sure, learn it but its NOT ESSENTIAL TO WRITE GOOD MUSIC.. In fact most perfect music whats been created in this world has been from guitars, drums, bass guitars. Sure, there might be some FX peddles and post-processing gone on in the recording (which is mainly how I get my sounds, sounding less-bland!) but just find YOUR way of writing music..
The amount of tracks what have just a simple bell synth in them, sure the bell is all pretty similar but its how its played, what reverb and delay you put on it and the context of the other sounds in the track what make it yours..
Here is a whole heap of banks
http://www.kvraudio.com/product/synth1- ... /downloads