The Galil has indeed been criticized for its weight. Probably the only thing "wrong" with it. Remember that in Israel, even the women are drafted into the service, so their equipment needs are adjusted accordingly.
One other thing to keep in mind is that the Israelis have repeatedly been burned when relying on foreign equipment - if a foreign country decides they don't like what Israel is doing, they can (and have) refused to supply spare parts, etc. Especially the French. (Yeah, I know - big surprise.) I doubt they trust the current Obama administration (again, BIG surprise - not!). So - the impetus is for the Israelis to develop their own weapons industry.