Adress reuse is not recommended for privacy, but it is definitely secure.
But how can you accept donations then? In order to accept donations, you need to make your bitcoin public address public, and everyone is going to be able to find out how much you got donated. For example, Wikileaks got more than 4,000 BTC donated, they have been using the same address since 2011, this is a huge problem. But what options did they have?
Is there any way to generate new addresses and guarantee that these addresses belong to you? For example, you click a "donation" button and a new address is generated each time. Im not sure this is possible without additional risks. This is hosted in a website so it could be hacked and pointed to ward's attackers keys so he receives the money.. for example.
Bitcoin still lacks privacy at protocol level.