I came across Dave Meltzer's Weekly Newsletter in which he posed the question: Why people watched Elite XC and not WEC this past week?  Some of the responses are below:

WEC is a victim of the UFC's success and saturation. I view WEC as UFC
lite, Diet UFC. WEC to me is guys that are too small to fight in the
UFC. That might seem silly, but that is really the way I feel about
it. Whether they want to admit it or not, WEC is to UFC as ECW is to
WWE.

WEC has great no-name fighters while Kimbo Slice is a huge star right now.
Kimbo is why I wanted to watch the Elite XC show.

Just wanted to respond your latest question, the reason I didn't watch WEC was simply because my cable service (Charter Communications) doesn't carry Versus. I did watch Elite XC.

I watched the show on Saturday night, but didn't even know there was a WEC show on Sunday, and even if i did know you would have to strap me down to watch it, what channel was it on?. I've been watching Wrestling since Strike force were the tag champs, I gave UFC a shot in the mid 90's and hated it and have never watched it since, of course I am familiar with the top names, but none of the middle guys. The reason people watched saturday and not sunday is this... Kimbo slice was a huge hit on youtube, I'm 25 and in college everyone would tell each other about his videos. He was a hit with regular people not just MMA fans, when people heard they could watch him for free on channel 7 they were interested. No one cares about WEC, at least none of my friends.

I watched the Elite XC show on Saturday but I did not watch the WEC show on Sunday. The reason for this is that I have the Dish Network and I do not get Versus unless I pay an extra $10 a month. I buy UFC every month on PPV because it is the promotion I enjoy the most in the world and their matchups usually intrigue me. I was not interested in spending more money for the WEC although it does not seem like a bad promotion.

i ALWAYS watch EXC because it's the fun spectacle UFC refuses to be. i never watch WEC because i already have enough trouble keeping up with UFC, let alone its kid sister.

boxing is a sport. wrestling is a sport. jiu jitsu is a sport. however, FIGHTING is not a sport. fighting is an emotional context. a fight transcends the "sport" being used in the fight. a fight is about love, hate, respect, disrespect, ego, pride, machismo, insecurity, confidence, and everything in between.

when i watch EXC, i get fights in a way that UFC/WEC seem afraid to be. kimbo slice, frank shamrock, cunge le, gina carano, etc. these are characters that make me EXCITED. the way the ultimate warrior made me excited in 3rd grade.

The answer for me is simple: I knew Elite XC was going to be on CBS, so I watched it. Unfortunately, I did not know that TSN in Canada was showing WEC (there was no indication in the TV listings that TSN was going to be showing it). I happened to catch the main event of WEC show Sunday night flipping channels, but it was entirely by accident. If I had known TSN was showing WEC, I would have watched that entire show, too.

So you have everything from little to no promotion for WEC shows to people feel it's an inferior product to the UFC to folks wanting to see circus acts instead of skilled MMA fighter's.  Some reasons are understandable while others I guess you could blame it on just being a casual fan of MMA.  My question would be: what type of show would it take to please everyone?