They don't have to decide to build around DeRozan or blow it up. They can (and are planning to) play DeRozan to stay compe ive while growing their young guys. In that vein, yes, it's important that they are close to the seventh seed. It's completely unimportant that they are close to 13th. They aren't trying to avoid the worst record in the league --they are trying to get a top-eight record in the conference.
They can afford to lose DeRozan for nothing. People keep acting like you sign or trade for players to keep indefinitely. But that's not the case. They made that trade specifically to remain a playoff team for two years. If they were so desperate to keep him, they'd've caved on an extension. Guys can walk. It's okay. The most valuable piece to Spurs' future is likely going to be the team's natural picks after bottoming out. Seriously acting like the team NEEDS to get say, Aaron Gordon rather than nothing is just bizarre. As I've said, I'm not against getting value for anyone on the roster. But worse role-players who are "better fits" with the inconsistent and underperforming guards on the team. Just get whatever draft or prospect capital you can and more one. If the guards pick it up, sign the role-playing forwards next year (there will be a number on the market). If they continue to disappoint, you get a higher pick and a clearer roster to rebuild.
Would I rather them make no moves? No. I think they should do something. They should consolidate the expirings on the roster into a legit rotation player. But I also think they are a better team than last season and will see the most improvement just by playing better. This is one of Pop's worst coaching jobs due in large part to missing the summer. If they can get on the same page, they'll make the playoffs. That's important to the team, especially more so than a middling role-player or even getting a high pick a year or so earlier than they're scheduled to.