Either the Rams really didn't like the interior OL options at each of their picks...
OR, the Rams like their current OL roster a helluva lot more than many of their fans do.
My guess?
Kromer sees possibilities that we're not seeing. He's been known to convert OG's to C successfully before, too.
Plus there's the UDFA pool opportunities.
Finally, there's the final roster cut opportunities as a last resort.
Clearly, the Ram brain trust preferred other options at #37 and at every pick thereafter.
So, once again the pros see things differently than the fans.