Cap numbers are not bullshit numbers to teams. They must plan their current and future rosters within the framework of the salary cap.
Cap numbers are not bullshit numbers to players. They get signed/restructured/cut and generally valued based upon their performance relative to their cap numbers.
The fact that cap numbers can be changed and manipulated within the framework of the NFL rules doesn't make them "bullshit." If there was no salary cap, none of this would matter in evaluating a player or his contract. Until that day comes cap numbers are important. Players' cap numbers are important considerations in evaluating players and their contracts relative to others; especially relative to others at the same position. In that context Kendricks' combination of performance, cap number and contract are bad when compared to other TE's.
If the Rams don't immediately cut Kendricks within a few days after the 2016 league year starts, then his $3,250,000 salary for 2016 becomes guaranteed. The Rams may be OK with this. They may not be and cut him if they feel like taking the $1,250,000 cap hit. We'll know what the Rams do by mid-March. One thing is certain, TE's of Kendricks caliber on other teams take up much less of their teams cap space.