It's not wrong man...different strokes for different folks. Personally i hate when i receive totally ground up weed and i never grind up all my stash, but a lot of my friends do. I like to have a bag of buds, and i always have a grinder on my person. However i see no problem with grinding it all up at once, because i can see why it would be more convenient for some.

I guess i just like grinding it up as i go along...and i smoke bongs a lot.