Capitalist is an entity who makes money because they own capital. Any actually productive activity (like investments into products/factories/people/etc) are secondary to extracting rent from owning the capital.
Now, for various reasons, few different things dominated over economy in the past:
1) Rate of return on investment for actual production, investment, etc was bigger than for rent extraction. Some of this was due to wars shaking things up, some of it was due to non-availability of (2)
2) Ability to grow capital purely by speculation was limited by physical & legal issues. This is where financial industry/engineering comes in - you can spend all your efforts on pure speculation, do corporate raiding etc. and be shielded from consequences. Same with earning money just by moving money around exploiting sub-second price differences.
3) (2) was less acceptable in the past - but became very much so in the present, even if there's constant grumbling about Wall Street - hell, the amount of people who claim that "maximizing shareholder value" is an actual law you're obligated to follow should be good point about it.
4) Corporate entities are a lot like paperclip optimizers - individuals in them can be individually moral and the corporate entity can still be an amoral profit chaser, especially in face of external stockholders. However, in the past, they faced different limits (legal & physical), different stockholders (less volatility and short-term juggling), and different social pressures.
All of the above combines with increased disconnect in many countries between different social groups and people starting to think that maybe, maybe, there's something weird. Then they look into how some people have been pointing that this is the "pure capitalism", maybe started calling it "late stage capitalism" to compare with more encumbered earlier forms, etc.