First, math. At the current coin price, if we had 5 equal-sized MG recipients, and kept say 25% of the MG slice as a reserve against volatility, then each recipient would get less than $1M/year. That seems far less than people had in mind, in the discussions of the Major Grant system and how it would create major new players undertaking roles on the scale of ECC. (And recall that ZF’s existing grant system will continue to serve smaller grants.)
Second, so far I haven’t seen indications that many teams of the requisite size and interests exist; I know of just 2.