When the students achieve great heights-mostly financially in corporate and business fields, they donate some amount to their Alma Mater. This is happening regularly. There are many well know names who contribute huge amounts and there are many who are not so widely known or publicized.
This happens to even we small ordinary individuals too. We also donate according to our capacity, attachment an suitable opportunity. We donate to the PTA s, for any infrastructure activities or some endowments for awards and prizes etc.
After achieving great success many people derive sense of satisfaction by spending at least a part of the money they have and and accumulated to some public welfare purposes. These are good for them and for society and hence welcome.
PS: please read the following news reports for just two examples:
1. "IndiGo co-founder Rakesh Gangwal made headlines for his considerable personal donation to his alma mater, IIT-Kanpur. Gangwal donated Rs 100 crore to support the School of Medical Sciences and Technology, following the footsteps of a long line of IIT alumni."
2."IIT-BHU had received over $4.3 million or Rs 32.23 crore donations from its alumni, including $1.3 million or Rs 9.8 crore from Ramesh Srinivasan, CEO of SaaS company Netcore Cloud, in September 2021, and $2 million or Rs 15 crore from Nikesh Arora, CEO of Palo Alto Networks, in November 2021. "
(source for the above: business today.in as updated onApril5,2022.)
There are many such examples.