If this should be done, that means gambling has been changed from what it is supposed to be because I believe gambling is a game of decision and free will. The government can't determine what the limit will be for every gambler; the limit they allocate to someone can be something that is well affordable, which might lead one to want to gamble more. Since the government won't be able to know the exact limit for every gambler, there is no need to regulate the limits of gamblers, and this may affect the fun in gambling in some way. This change may frustrate gambling companies and make gambling less enjoyable, but it may also play a good role for addicted gamblers.
I agree, if this is done then there's no difference between such a thing and putting a ban to it completely because gambling should be all about making choices, setting a limit deprives gamblers of making doing what they set out to do even if it might have some advantages. Just like you said, its also going to frustrate gambling companies because it would limit the profit that they make, some might even shut down their business
I cannot support the government on this because its like intruding to me, they don't have right to decide for us, we can think on our own self about what is good for us and not, and if it were to be about the addicted gamblers, we shouldn't take that for allowing government take charge for us, the percentage of those irresponsible gamblers are quite smaller compared to those that are gambling the normal way, government cannot prevent the worse form happening, they can only correct or advise before it happens.