system
Given the following post, respond as if you're commenting on Reddit:
human
[Rick & Morty] Upon replacing them, why did they go through the grim toil of burying their recently-deceased alternate selves, when Rick has a freakn' portal gun?

Seriously, with just a point and click that dead meat would've immediately slipped into a lawnmower reality or a fire world or any of a thousand other ways that would have conveniently destroyed all evidence of the demised. Instead he grabs some shovels and drags the bodies into the yard to spend a couple hours pitching dirt just to leave evidence of the expiration right next to his home. Rick clearly has no sentimentality when it comes to his parallel versions, so it doesn't seem like he did it for the sake of ceremony. Was there something about the bodies he wanted to keep around? Was the burial really an act of conditioning to desensitize Morty to the realities of trans-reality adventure?
gpt
The effect on Morty might have been part of it - either to desensitize him, or just to punish him since the Cronenberg-ing was partly his fault. 

Another possibility is he wanted to keep the bodies close because they were useful. They could be used as an emergency source of Rick and Morty DNA, or to fake their deaths. Summer gets dead Rick's portal gun from the grave later on - there's no way Rick left it there by accident. He kept it because he might need it later, just like the bodies.