Slow science is a recent term to promote a stronger focus on solid, curiosity-driven research instead of quick and sloppy works to evade the "perish" part of the "publish or perish" paradigm. Fast science like fast food makes things happen quickly, but limits our scope to hasty fry-ups.
Why do authors publish so many papers?
It is easier to focus on many papers instead of fewer more substantial works:
Randomness in peer-review favours quantity of submissions over quality
Plenty of exotic problems or problem variations that are easy to solve
Appearance of substance can be achieved by overcomplicating things
Substantial works are more disruptive and tend to meet more opposition
It is often not scrutinised how well a paper meets the promises it makes
There are various incentives:
Authors with many papers on a subject are perceived as experts
Career progression can be tied to quotas
More papers means more say on which authors receive most citations
There are no penalties:
Padding a research portfolio never hurts
The true scientific value of a paper is hidden away from plain view
Do authors perish if they focus on fewer, but more substantial works?
In some disciplines authors may have the option of targeting more selective venues that
set higher standards for quality, which can then be very prestigious. Yet many of the previously mentioned issues remain.
The selectivity of venues may also not be very well known and the prestige only extend to certain subcommunities.
Matters are made worse by the fact that it is completely subjective, e.g., only looking at acceptance
rates of a venue indicates very little about their quality.
How could well-intentioned researchers be helped?
Try to make reviewing in selective venues less random
Prioritise quality over quantity
Consider both the best and worst publications in a research portfolio