The other way around. "Blank check companies" have existed for many many years, but were a relatively rare instrument and did very bespoke deals. Most investors never heard of them. In recent years, a standardized deal emerged that became known as a SPAC (and all the recent flavors of the month). If you look in SEC regulations, you'll see references to "blank check companies" all over the place.

Interesting. Why are SPACs getting a bad rep? Is it because of the acquisitions of shady companies or is there an underlying issue with the process followed by SPACs?

SPAC sponsors get essentially a free money trade when they merge with a company; usually this results in merging with sub-par companies with bad numbers (no revenue or even product usually) so investors can cash out massively without the company really needing to succeed at all

Case in point: most SPACs have fallen anywhere from 50-70% (evtol/lidar/battery companies) over the past year due to the fact that most don't have either a working product or poor numbers