Rav Hirsch explains on Beshalach 16:4 that He is not providing the food as a result of the dissatisfaction, but to teach them the lesson that He has already prepared the food in order to teach them the lessons that they must learn.
When I led the people into the desert I had decided to provide them
with food in this way.
Hashem is now teaching them that they must be ready to accept that Hashem will provide each day the necessities of that day. 16:5 shows that everyone will be granted the precise amount decreed for him no matter how hard he works and that the sixth day will be double so that they will not need to work on the Shabbat.
Rav Hirsch points out in 16:6 that the quail is due to the complaints, but here too it is a lesson that Hashem hears and understands everything that is going on and pays attention to every word.
The Bnai Yisrael were at this time like little children who do not understand that they can trust that they will be provided for. Thus they cried as soon as they started to feel hungry and did not yet understand how they were to be supported.
The complainers starting in 11:1, the people did not pick up on the lesson that they should have learned. They started to complain and Hashem caused a fire to break out at the edge of the camp. They now cried in fear and Moshe prayed and the fire died down. However, far from learning their lesson, they actually pushed themselves to be worse. As Rav hirsch translates 11:4
But the rabble that they had taken in among them goaded themselves on
to desires and then the Children of Israel also again began to weep
and they said: Who shall give us meat to eat?
That had been getting the man which was miraculous sustenance and provided everything they needed. Hashem said the He would provide the quail for a month until they were sick of it. This would show that they are going to far in their complaints. As it says in 11:20
But even for a full month until it comes out your nose and nauseates
you. Because you have despised the Lord Who is among you, and you
cried before Him, saying, "Why did we ever leave Egypt?"
However, even this was not enough for them. As Rav Hirsch said on 11:32
Both greed and mistrust in the assurance that Moses had brought them
are shown in this rush to gather the quails.
As a result, the lesson that would have taken a full month, fell upon them at once.
Rashi had said on 11:20
But even for a full month: This [concerned] the [comparatively]
virtuous ones, who languish on their beds and later their soul
departs. But concerning the wicked ones it says, “the meat was still
between their teeth [… when the anger of the Lord flared…]” (verse
33). This is how it is taught in the Sifrei (Beha’alothecha 1:42:20),
but in the Mechilta (Beshallach, Vayassa 3:13) the opposite is taught:
the wicked ate and suffered [as a result] for thirty days, whereas
[concerning] the virtuous-“the meat was still between their teeth”
[thus, they did not suffer prolonged agony].