The answer to your question, as other commenters are pointing out, is in the "seem". They seem to have less flagrant issues, but that's just appearances.
While tech still has a very long way to go, at least speaking up is becoming acceptable, and won't bar you from the industry for life. An Uber engineer who speaks up will never work for Uber again, but she can still find work in the industry (if she so desires). Someone who speaks up on Wall Street will be "marked" for life and never have the opportunity to work on Wall Street again.
You're absolutely correct about being "marked" on Wall Street.
Unlike tech, most professional services (banking/consulting/law), don't require particularly skill, but rather the right pedigree, connections, and social background.
Getting a job in IBD at a bulge bracket means years of striving: the right schools, the right social networks, the right way of "talking", the right "look". The rewards are massive: $100-200-300K bonuses even as a young analyst is the the norm. Loyalty, being able to "eat shit", etc are the traits most admired on the street. Being a "troublemaker" and speaking out against harassment (not even just sexual in nature, but just plain bullying/hazing) earns you the label as "weak" and out of a job. If you've been striving all your life for one of these coveted jobs, you can imagine the immense pressure to grit it out, collect your fat bonus, and drink, snort, and purchase-expensive-toys your stresses away.
While tech still has a very long way to go, at least speaking up is becoming acceptable, and won't bar you from the industry for life. An Uber engineer who speaks up will never work for Uber again, but she can still find work in the industry (if she so desires). Someone who speaks up on Wall Street will be "marked" for life and never have the opportunity to work on Wall Street again.