Well, in general this is true of entertainment - the best usually has that "little extra special bit of love" injected into it, and when something is a pet project, it shows, even if the end result isn't good. This happens a lot with movies, and it's probably why the comparisons between games and movies are so common; for larger productions in both mediums, no matter what you do you have to treat it like a somewhat industrial process due to the sheer number of people required for each production. A smaller team can of course have a more personal touch, but this usually means longer release times and more limited resources.

A lot of the time it just really depends on the motivation behind the director. Keep in mind that some of Nintendo's most successful games were from simple observations on the parts of their creator, like Miyamoto watching ants while he was gardening and coming up with the basic concept for Pikmin. Most yearly release games will suffer just because they are yearly release games. Same with yearly release movies.