Well, for a start, not all of the original Tamagotchi things were pets. Remember Arukotchi? It was a dating simulator-like pet.
As for Tamagotchi losing its meaning. I don't believe it has. I think its original meaning, from the very beginning to right now, was to simulate life in some way or form. So far, the only Tamagotchi I've seen that doesn't simulate life is the Angelgotchi (it simulates afterlife).
And the rest of them, as well. The V4/V4.5 simulate growing up, education, and the working world. The Keitai/Akai, V2, and V3 also simulate life, more like a teen or preteen life, as it seems. TamaSuku focuses on education, Famitama focuses on a family life...you get the idea.
The games, anime, and movie are all things that go along with a trend like Tamagotchi. It's no different than what happened with Pokemon. It started off as one thing, with one concept, and suddenly burst into millions of other ideas.
As
Bandai said, they're not hoping for Tamagotchi to be a giant boom like it was back in the old years. They just wanted to bring it back for the new generation.
~OM21