Why not both? Apple makes a killing from selling media on iTunes and with a healthy profit margin. A better DRM helps protect that golden goose just a little more.
That was a marketing strategy, not something that was necessarily important to Apple. Apple did that to enter a market dominated by downloaded mp3s. Now it doesn't need that position. And besides many people have left the company since then, so a decision change wouldn't be strange.
More recently, the Movies and Apps parts of iTunes are very much DRM encumbered.