I do not agree with this statement because the law of diminishing marginal utility has the following exceptions.
1. Hobbies: - it is believed that in the case of certain hobbies such as stamp collection, antique (historic) collection, etc. MU goes on increasing with acquisition of additional units. But here the person does not collect the same types of stamps, and therefore, the assumption of homogeneity is not fulfilled.
2. Drunkards/Drug addicts: It is believed that every dose of drug or liquor increases utility to the consumer. But in the case of drunkard or drug addict, there is no rational behaviour is assumed.
3. Miser: -A miser’s greed increases with the increases in the stock of money. But here miser displays an abnormal behaviour in hoarding wealth. Therefore, the assumption of rational behaviour does not apply.
4. Music and poetry: -It is believed that more poetry and music give greater satisfaction.
5. Reading: -Reading on more books provides more knowledge and in turn, greater satisfaction. But the reader in search of knowledge does not read the same book every now and then. Therefore, the assumption of homogeneity does not apply.
6. Money: it is assumed that an individual gets more satisfaction with more money and he wants to have more of it. In the case of money, it is to be noted that money alone does not satisfy a want directly. It only acts as purchasing power to purchases goods and services. Goods purchased with money do have diminishing marginal utility.