Two things are incorrect:
There are more exchange platforms hacked compared to 5 years ago. Just look on the web, there is a hack every 3 months and it includes more millions $. But we could say it's something normal since more platforms are online compared to 5 years ago.
That is 28x jump in average hack value from the pre-Gox era
and despite all the changes they make (2fa, etc...)
140 cryptocurrency exchanges have been checked one by one for basic security issues. It doesn't mean these exchanges have vulnerabilities but they should improve some basic security controls