There is PLENTY of scope to making a shooter version of XCom. The problem is that nothing that has been offered so far is it. The initial screenshots and info about Enforcer implied that it would be as good a shooter version of X-Com as could be made. Then they made it into a pile of poo. Perhaps if Enforcer had never been made, there would have been warmer reception to XCom.
Still, a reboot of X-Com might be awesome, it might also be shit. Theres a fine line to tread here. If they literally remake the original game, it won't do well. I already have the original game in 2 different formats. If they stray to far, the fans won't buy it and "mainstream" gamers probably won't either.
Of course, there is an out. Make a new game, with its own name. the UFO:After* series did well and didn't need to brand itself as XCom.