Despite what many have been told, studio monitors are not necessarily all that different from high-quality hi-fi or 'stereo' speakers. Like the best hi-fi speakers you may have ever heard, they should not favor one kind of music (or sounds) over another. Studio monitors are meant to be ultimately revealing, adding as little color as possible. Ruthlessly Revealing in fact.
Listening on quality monitor speakers can be humbling: poorly-recorded tracks can sound harsh and/or boomy on full-bandwidth, low-colorization speakers. The sad reality is that some iconic tunes which may sound pretty great on a boomy roadhouse jukebox may sound less so on a balanced loudspeaker system in a room with neutral acoustics.
In the worlds of audio production and post-production, people generally want to know that the speakers they hear & work on at another studio in town uses the same amp that another studio uses. So to arrive at a more consistent specification, users have gravitated to self-powered (so-called active) monitors. Now you don't have to worry whether the studio has a particularly sweet-sounding monitor amp. It's built in and optimized (as far as power) for the driver(s) it's powering.
You may be thinking, why not just go to a hi-fi store and buy great stereo speakers? For one, for comparable performance a hi-fi speaker will be more expensive. They probably have nice-looking wood veneers - somebody has to pay for that. Secondly, hi-fi stores have historically operated on hefty markups. And most hi-fi or stereo speakers probably require a separate amp, unlike studio monitors that are mainly active (amps are built in). Lastly, there aren't many true hi-fi shops left, that biz mainly went to the big-box retailers who cynically figured people will buy anything flashy - as long as it's cheap.
And most of the remaining 'boutique' hi-fi shops decided the only way to stay in business was to cater to affluent (and/or extremely gullible), people who would think nothing of paying thousands of dollars extra for fancy cabinet finishes, esoteric speaker cables and tuning pods (look them up, they make buying a pet rock look like a rational purchase, and certainly a bargain in comparison.)
At the end of the day, there are different technologies that can be employed to design great studio monitor speakers. Two-way designs vs three-way designs with dedicated a mid-range driver. Sealed vs ported (bass-reflex.) Ribbon tweeter vs dome tweeter. Metal dome tweeter vs clothes dome tweeter, etc. Despite what you may read, different brands can each have their own way of achieving excellent results. Working with a good dealer can help you find speakers you'll love for a long time while trusting the results you arrive with.