I wasn't aware of Hooked on a Feeling before GOTG. I remember the dancing baby, but the thing was hideous and ridiculous, so I didn't pay much attention to it. The music certainly left no lasting impression, obviously.
Looking it up, the song was a very minor hit in the UK in the 60s. I would be astonished if more than a tiny percentage of the GOTG audience actually remembered that. I think "obscure" is a fair label.
At the end of the day, it's a fairly mediocre 60s pop song. Now, by virtue of being a 60s song it's automatically immensely superior to any modern pop song, but by the standards of the 60s it's mediocre. It's no wonder nobody remembered it.