Well, on T-mobile smart phones with HTC Sense/Android 4 (HTC One S, for example), you cannot really uninstall (as in "remove") any of the pre-installed bloatware apps unless you root the phone, but you can disable many of them. Phone-operation-wise, the effect of disabling an app is the same as that of uninstalling (i.e. removing) it.
Yes, MobileLife Contacts can be disabled!
Here are the steps (assuming you are running HTC Sense 4):
1. Settings - Apps - All
2. Disable Customization Setup.
3. Disable Customization Settings Provider.
4. Disable MobileLife Contacts.
5. Enable Customization Settings Provider (yes, in the reverse order).
6. Enable Customization Setup.
It appears that quite a few T-mobile's "pest apps" can be disabled this way. Have fun experimenting, but don't blame me if you screw something up (a standard disclaimer).
UPDATE FOR HTC SENSE 4+
It appears that in HTC Sense 4.5 (aka HTC Sense 4+) you can't disable Customization Setup and Customization Settings Provider from the GUI anymore. Thanks to Marco Duran for bringing it to my attention.
My educated guess is that you should be able to disable them via terminal (you will need to install a terminal emulator) using something like this:
pm disable com.htc.CustomizationSetup
pm disable com.htc.provider.CustomizationSettings
Then, once you are done getting rid of MobileLife Contacts, you can enable those back:
pm enable com.htc.provider.CustomizationSettings
pm enable com.htc.CustomizationSetup
Unless HTC introduced some additional dependencies in HTC Sense 4+ (which I don't know), this should work, but I cannot guarantee it as I have not tried it myself.
UPDATE: Unfortunately for most owners of phones with HTC Sense 4+ out there, this method works only if you are superuser, which means that your phone has to be rooted.
P.S. On a smart phone running stock Android 4 (not HTC Sense 4) just do steps 1 and 4 described above.