There is no reason to switch from your parents’ customs unless there is a very good reason. But you need to understand your minhag properly.
for example, many Sephardim hold by “when in Rome …” (not my words, afrom a Sephardi Rav). Thus, they had a turban in Baghdad, and their children will follow their minhag by wearing a black hat in Lakewood.
Chasidim forefathers switched from other minhagim to become chasidim, so they should not complain that their children switch to yeshivish or other chasidus.
People whose parents rebelled against religion, will respect their parents’ minhag and rebel against their non-religiosity.
OP focused on the rare exception: – Litvishe is most coming from people who were stubborn against modernishe, chasidishe, goyishe, etc, so there is a good reason to stand by their dress without changing. Those who do follow previous renegades, but disrespect their elders who chose not to change against all odds.