Answer:
Because lytic virus reproduces its phages immediately leading to bursting of the host cell for the new phages to leave.
Step-by-step explanation:
Viruses employ two major cycles to reproduce themselves namely: lytic and lysogenic cycles. Lytic cycle involves the entrance of the viral cell into its host, using its host's replicational abilities to reproduce and bursting of the cell.
The lytic cycle is carried out by strains of virus called VIRULENT STRAINS. They use the host cell to produce many virions and destroy the cell by lysis in order to leave the host cell. This accounts for the reason they DO NOT STAY LONG IN THEIR HOST CELL.