You could also prepare 3 small zip bags with 3 different flavors. That way you don't have to carry 3 whole bags, but the equivalent of only one bag, and each meal is self-contained. No scooping stuff and measuring involved either, since you'd have done that in advance
Portioning like I do is easier with big bags than small bags. If they were to make 700 kcal single meal bags, I'd have to open 3 of them to make my usual 5x400 kcal zip bags (which is convenient for me, because it's the perfect amount for 5 weekdays, so I just prepare them on Sunday and bring them in on Monday, and done). It'd be both a waste of packaging material, and of storage space, because it's usually easier to stack big bags efficiently than small ones!
I'd actually argue the other way and prefer bigger bags. For example, when I buy Whey Protein, I usually can choose between 1kg, 2.5kg and 5kg pouches. If Queal were to do the same, I'd always buy 5kg because it'd probably be cheaper, I don't care about size since I portion everything anyway, and it'd mean less package waste.
Well, I do.
...yet I just did that?
At the risk of offending your sensibility, I must say: I think you are very self-centered. Just because Queal does not offer single meal pouches though this'd be more convenient for you, doesn't mean others must agree.
You are entitled to your opinion, but please, do not try to dismiss others'... that's a good way to get them not to listen to yours anymore.
tl;dr: You prefer single meal bags because of your reasons above. I prefer bigger bags due to the reasons above. And that's cool.
I'm also all for more options, so if it was sustainable for Queal to offer variable size packages, that'd probably be the best thing for everybody!