Why does top command fail to exit successfully and keep running in background?

Issue

• Why does top command fail to exit successfully and keep running in background as follows?

# ps -ef |grep top
root         5     2  0 Jan31 ?        00:00:00 [stopper/0]
root         8     2  0 Jan31 ?        00:00:00 [stopper/1]
webapp    6993  6938 26 Feb25 ?        5-10:17:24 top
webapp    6994  6813 26 Feb25 ?        5-10:05:40 top
webapp    6995  3267 26 Feb25 ?        5-10:07:38 top
webapp   13611 13390 26 Feb26 ?        5-01:52:02 top
webapp   20469 20415 26 Feb25 ?        5-07:16:33 top
webapp   20693 20639 26 Feb25 ?        5-06:46:16 top
webapp   21129 21070 26 Feb25 ?        5-09:40:30 top