Just because you are simplex doesn't mean there won't be anyone else. I often chat with a couple of hams who use 146.460 near here on their commute from Parker to DTC. That this is an easy frequency to remember was in part the reason Nathaniel came up with RS002 through RS004 for simplex.
It's all about how you make your call.
Saying "KD0GWX, mobile and monitoring." implies that you are asking for an open QSO. Technically on simplex you probably should say "CQ CQ CQ KD0GWX CQ CQ CQ." but due to the fact that VHF is line of sight and you are not looking for a DX contact this is not really necessary. However if you say "K0NAK, KD0GWX calling." or "KD0GWX calling Rising Sun on frequency." you are implying that you are looking for someone specific and generally you will not get an unknown ham returning the call until you announce that "Nothing heard from K0NAK, KD0GWX clear and monitoring." If you don't care to chat, then just say "K0NAK not heard, KD0GWX clear." and then if you switch frequencies or turn off the radio there is no expectation that you would still be on frequency.
And not all hams talk about gout and Sam's Club. Believe it or not that we're getting Rising Sun members on the air more than a few hams know of us and sometimes the conversation turns to 4WD and Moab. I spent probably an hour at HRO talking about Moab with one of the sales guys who was born in Utah and was planning to take his Rubicon out there to show his wife where he grew up. Also using the repeater gives you immediate feedback that your station is operating correctly or at all, when you hear the repeater tail you at least know the repeater is listening and you are transmitting a sufficient signal. Unless someone returns your call you have no idea that your coax isn't broken or your radio finals aren't blown.
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'08 Tacoma TRD - Donna