Are you implying that this should happen overnight? over the course of 2-5 years? over the course of 20-50 years?
Because I bought a pair of Sennheiser headphones from a local audio equipment selling website and this in bumfuck South Africa we're talking about. I doubt the merchant is even aware they accept Bitcoin as "legal tender" since it happened through PayFast and was completely transparent to them. The point is _I_ could use it as legal tender. So from my point of view it has incredibly amount of value.
The OP commented: "because more people will accept it as legal tender." the word "more" implying that at least one or more people already accept it as "legal tender" as per whatever definition he uses of "legal tender".