Yes Joe Biden pardoning his son is sleazy and transparently corrupt, and claims to the contrary are best answered by Biden's own previous statements about why he wouldn't do it.
That said, the man is a genocidal bigot who's spent the last year exterminating a civilization so I find it a bit absurd how much time and energy is being spent on this trifle.
If you're bothered by his genocide then this barely registers as an offense by comparison.
If you're not bothered by his genocide but are breathlessly ranting about this then you have your own massive moral failing to worry about, one far greater than a corrupt politician pardoning his criminal family members.