I like how plebs exposed themselves by saying the butt gun was disrespectful when it's from the original.

There was an extra layer of implied tragedy that the 2009 film didn't really emphasize. When Toby was alive, Tenma was too busy to spend much time with him. After Tenma rebuilt him as Astro, who in that movie explicitly had Toby's memories and personality, Tenma wanted to spend more time with his now "revived" son, but quickly cast him aside as not truly Toby. The reason was he thought Astro was acting differently than Toby, but there wasn't much indication that Astro's personality was any different. The implication was that Tenma was so distant from Toby that when he was finally determined to sit down and spend time with him (or rather Astro), he didn't even truly understand him and threw him away because of his own misunderstanding of his son's personality.