Generally speaking people who need mental health help are going to be more easily discouraged by a negative interaction than the general population even if they can afford therapy in the first place. In the US at least there's also a shortage of therapists, meaning you might have to wait a long time to see anyone at all. And in my experience there are a lot more bad therapists than good ones (though assholes of this level are probably rare).

Honestly if it were me I'd just save myself the trouble, read a book on CBT and get some antidepressants. But that doesn't work for everyone.

Sure, you just look for someone else, but it'll take a while, and then you don't know if your new therapist is also an asshole. And the last interactions with therapists have left some scars that might discourage you from even looking for a new one. Besides the mental health issues that you have might already make it hard to just pick up the phone, which doesn't make looking for a new therpist easier.