Bitcoin Gold and Bitcoin Cash are not serious threats for Bitcoin and I don't believe they will have any significant effect on the long term on the echo-system. However, forks have the advantage of forcing open debates around serious issues.
That is very true, we saw what happened to bitcoin cash, it wasnt taken seriously and after bitcoin gold it will also be considered as a shit coin, bitcoin gold will also be useless just like bcc, if all these forks keep coming because people want more money and power bitcoin will only rise, these forks should stop immediately because they have no value and bitcoin will be number one.