While watching TV with my kid, I've watched various advertisements of gambling nature (let's say for example, Rummy123, RummyCircle, A23 Rummy, etc.)
These are all specifically Indian ads, but I'm sure you may have seen various gambling advertisements, some banners at boundaries when cricket is ongoing, even in any other sport. How would a kid ignore those things, they might just come and ask you about what is it. Till when can we lie to them? Don't you think that the frequency of such ads must be less in order to let the kids not get trapped into gambling and don't do it at such a small age?
It depends, and if it is in a normal show/program, that is the irresponsibility of the advertising regulation agency of your country, they should even be fined or their boss resign. But in your case, nothing is bad about it. You know what, a lot of things are happening that people are only turning a blind eye to, but later, it will be an issue. I hope they do not make that mistake in important programs that children can also watch. Gambling is an adult activity and inasmuch as the law doesn't want the underage to participate in it, they should not tempt them as well. It is highly irresponsible of them to be advertising such unless there is a disclaimer in the entire program where they warn of 18+. If not, parents can even sue them if they want, only that people do not think towards that angle.
Now, for clarity's sake, it is not taboo to advertise gambling companies on TV, but programs matter. For example, in football programs and others, such can be done. Still, in most cases that I've witnessed, they will just have the banner hanging around a section of the screen, and not saying anything relating to gambling directly. By this, adults will fully understand what they mean.