The only reason we recommend not making an all-fruit Blast is to help prevent any rapid spikes in blood sugar or a Blast with way too much sugar. To help (without using veggies), you could be sure to add in mostly low glycemic fruits like berries. If possible also add in some protein and/or healthy fats (nuts, seeds, nut butters, etc.) to help slow the blood sugar absorption.
Yes, you can "make up" for it at lunch, but if you ever have the option to toss in just a bit of leafy greens, you can reap bonus points!