Actually you're saying several different things and I'm just addressing some of them.
You don't understand why he hasn't been signed to a contract, he hasn't done anything deserving of being signed to a contract. How has he proved any worth as a deep bench big exactly? The only times he's ever put up numbers that aren't trash is during stints of extended playing time (not bench minutes) when teams have been desperate.
There are plenty of differences between Earl and the other guys you mention. Barron is 31, 7'0 but skinny as hell with no shotblocking ability.
Mozgov, Mahinmi, and bigs similar to them are young, with true C bodies and the potential to actually blossom into real bench assets or more. Comparison to Scalabrine is silly as Scalabrine had range out to beyond the 3pt line which is always a big plus where big men are involved.
I'm aware you weren't emphasizing the game as being amazing, you just stated that his contributions in this ONE THROWAWAY GAME are bigger than "many of our ageless bigs" which is ridiculous. Sheed, Camby and KMart have contributed more to this Knicks team in a handful of injury-ridden games than Barron has contributed to all the teams in his entire career.
You do realize this is a forum right? A place to discuss and debate. How exactly is this an argument? Just because I'm challenging things you say that I have a differing opinion on doesn't make it an argument. If you're so sensitive that you don't wanna be here because people disagree with you, then an internet forum isn't the place to be brother.