I think the news about your achievement with Bitcoin is getting to them haters that's why he is trying to talk you out of it, you said he is the most success in the family? People like that won't want anyone else to take their place as the bread winner of the family, I will be careful with such soul.
It's the way you personally understand it, because from my understanding the uncle made his point through the news he heard from government and also people who trade Bitcoin, sometimes do you know that some primitive people find it difficult to believe on bitcoins, so many of them trust and rely on fiat currency, the uncle is making an emphasis base on what it understand and the kind of information people process to him concerning bitcoin.
And that is wrong and we can't hear good from those who never know about Bitcoin but all are negative and blaming just like what his uncle did to him. His reply is a little bit harsh for me but I understand it was due to his emotions, well, that is exactly what happens when we can't control our emotions as we are talking about what we understand and make him educate as well.
Anyways, it was really hard to gain support from our family in investing in Bitcoin, might there be some but most will disagree. That is why I've preferred to keep it secret rather than get distracted by them.