I found this Chiffboard post and the discussion that followed worthwhile. It began with the following quote from Willie Clancy:
Get a grasp of the Gaelic tongue and develop a love for it. Go to the Gaeltacht and the old people who have it and learn it. I feel that a knowledge of our language is essential if you are to express the true spirit of our music and, as the saying goes, "Don't settle for the skim milk when the cream is at hand". Apart from that have patience; learn to walk before you run. You might have a flair for the music, you might think you're good at it, and you might be tempted to plunge ahead without perfecting your technique; well it might be in your head but your fingers will let you down. So, start playing early and develop your technique with patience, practice and perseverance.
I can remember being frustrated years ago when I realized that I was a much better driver than I was a musician simply because I drove the car more often than I practiced playing, despite telling myself that music was more important. No matter how much you say you value something, doing is how we learn.
So will learning Irish make your reels better? Maybe.