This is a tough situation for Philly - [dang]ed if you do, [dang]ed if you don't.
If they don't give him the max extension somebody will certainly give him a max dea, and if he somehow gets healthy and becomes a top 5 center then they'd be shooting themselves in the foot.
If they do give him the extension and he plays 30 games in the next 2 seasons, it'll look like the worst move ever.
I honestly don't know what I'd do in their place.