SNEKUL is right that the MSIEXEC /X {product code} will work.
Problem with pushing/uninstalling from an existing MSI package, is the MSI package needs to be present and the reboots that it requires.
Rebooting 10,000+ machines over X number of locations simultaneously will likely choke the heck out of the bandwidth unless explicitly defined on different servers in said remote locations.
If the "logon server" is on the other side of a 2MB pipe and you have 100+ clients accessing the same 75 - 80 MB file (msi package) to uninstall, insta-death to the LAN. If other servers or ressources require some bandwidth to function, more loss to possible necessary infrastructure.
After the rebooting is done, possibly other clients will be trying to access the same said logon servers and they will be unabel to communicate with it due to the bandwidth being choked up.
If for some reason, not all clients are the same version, then you also face the problem of multiple {product code} for uninstallation. More good times in trying to locate them all.
Basically a rock and a hard place.
Also, as an administrator and avid user of these forums and others, I DO NOT believe moderators should allow "bullying" on these boards by end users telling other users how great product A is and what a mistake it is to go to another product. We are supposed to be a community of IT trying to help one another and address issues.
He was asked what product he was considering using and than the 'flaming' started. As others have stated, there are sometimes internal reassons why a company chooses to go from one vendor to another- be it Hardware or Software.