A gift is given for you to enjoy, it was your birthday, you got a wii. I'm sure you were ecstatic at the time
Theres no way to gauge your enjoyment by hours, that isn't really accurate or fair. I played at least 2 hours a day for the first 4 months or so, then I didn't play my wii at all for like 6-8 months. Partly because I was in a temporary living situation which didn't involve a TV. Over the last month I've been playing it alot again.
What I'm trying to say is that theres no need to feel bad for being occasionally disinterested. 176 hours is a good chunk of time, you've definitely used your wii and enjoyed it. I'm sure there will be games that peak your interest again in the future. Don't fret, do what you enjoy, whether that be playing wii or something else.