It isn't a matter of "spite". Many developers simply cannot afford to have all the incarnations of Amigas that are out there. Nor the time to develop for all of them. It may be that the developer cannot afford a 68K Amiga, a PPC Amiga, and a PegasOS. The development software can also be expensive.
If you visit the web site of the Sputnik developer you will see that he doesn't own any Amigas. Just a Peg board. And he's using a donated version of Cubic IDE for development. Maybe you should offer to send him one of your 68K Amigas or send him some money to develop Sputnik for the other systems. I'm sure he'd appreciate it and it would also help the rest of the community.
Here's the link to his site:
http://www.ppa.pl/khtml/index_en.php
