Further, in some fields (biomedical) research takes so long, and top-tier journals are so selective, that a lot of work just never gets published. Slowing that process even further would wreak havoc on already way-too-long graduate careers. A really pernicious effect of some bosses who 'only publish top-tier-quality work' is many students get stuck with years-worth of negative results, and do not get to either move on or publish their work.
