The ancestors of the family in question come from Poland. At least the known ones. Which is indicated by the surname. Some of them changed their surname after coming to Poland, due to some pressure, if I may say so, coming from the workplace of two brothers: Józef and Walter. This was not, of course, any officially expressed pressure, but a suggestion arising from the circumstances and from the working environment.
All in all, in the motherland they could change the name too, but for other reasons. For example, from the bad association of it with a common noun. But in a foreign country they could not even guess the etymology of this word, so it did not suggest anything to them either. In the country of their ancestors it may have been associated with treason, which gives a bad connotation. It might suggest that a distant ancestor, or rather one of them, had committed treason. So he received such a nickname, which remained with his descendants, and when nicknames became surnames, the surname also remained in this form.
So, as you can see, the reasons for changing one's surname can be varied. One may also have a surname associated with some well-known criminals, which may also somehow influence the valuation of a given person. This is not a legitimate reason, but, as we know, who confuses spontaneous reactions with rational justifications.
There is a film director and producer in the country of his ancestors who also changed his name. The aim was actually similar to that of the above-mentioned brothers - that foreigners would be able to pronounce and write it easily. Anyway, he changed his surname, probably when he was a teenager. Already then he planned to be a famous director. He realised his plans. As you can see, some people succeed. Maybe it is due to stubbornness. Maybe it also results from knowledge and experience. It may also be based on character traits.
When discussing a name change, it is worth looking at the legislation. There certainly used to be some, but probably not as restrictive.
We now have a law which states that a name change is only possible for good reasons. These are not specified. This statutory statement is followed by the phrase "in particular", which means that the so-called catalogue, or set of reasons, is given as an example.
These include, for example, the ridiculing nature of the name or the fact that it is not in keeping with human dignity. Thus, the names could be: donkey, fool, ram, cymbal, etc.
The reason may also be a surname that someone has been using for a long time but has a different one in documents. The name can also be changed on this basis. This also includes changing the order of the forenames recorded in civil-status records.
It is possible to change a surname if it was changed illegally earlier. That is, for example, by some fraudulent action, by sending a false application to the authorities, etc.
A change of surname may also have been made ex officio, by spoliation, which may be considered unlawful. Therefore, in such cases, the change is admissible, as a return to the previous name.
However, other reasons can be found as long as they are well argued.