I think Thomas Edison said that quote
Yes I agree with this, somewhat. Let's relate this to a businessman. Do you realize how many "ideas" people can come up with, but an idea is worthless if you don't have the initiative to take action. And this is what Thomas Edison meant. A businessman, or "genius" may have wonderful ideas, but if he cannot take the hard work or initiative to promote or make his wonderful ideas, the idea is worthless.
Same thing with composition. I believe a certain amount of effort (perspiration) is needed in order to become a successful composer, however I think maybe a little more than 1% inspiration is required. If you simply have no interest in composing, you will not put in the hours needed to become successful.
I started out a very bad composer. Nevertheless, I had the inspiration to compose for some reason, (alot more than 1% in this case), but I also worked hard at it every day for hours. In my case, I assume I spent on average 2 hours a day composing for 10 years. So that is an estimated 7300 hours of my time put into composition during my 10 years of composing, and I still have much to learn. Those 7300 hours of perspiration has tremendously aided my composition abilities, and that inspiration is what made me put in the 7300 hours.
So, in my opinion, I do feel hard work needs to be put into composition, even if you have a good deal of talent.