People don’t like having their secrets revealed especially when those secrets reveal something untoward. If their behavior is corrupt enough that it needs to be exposed, it’s not a far stretch to suspect that future behavior could extend to retribution against the whistleblower.
Of course it’s also reasonable to suspect that the real whistle blown in this case is actually below Schiff’s belt. Could be a genuine whistleblower, but is probably just a partisan **********.
In today's climate, I'm betting that's a pretty safe bet.