E175 pilot here. The jet is capable of autoland and also has heads up displays. Essentially the same capability as any modern jet.

However Skywest only gets options that allow for Cat ii approaches and only trains its pilots for this. As a result they need visibility to be above 1200 feet to land whereas Horizon only needs 600. So there are times that Horizon and mainline can get in but Skywest cannot.

This is all spelled out in out regional contracts. If AS wanted Skywest to have the 600' capability, it would raise the cost of Skywest feed.

So as usual what you were told has a small kernel of truth but is essentially not correct. The plane is every bit as capable but as a cost saving measure, the training is not done to allow the full capabilities of the airplane to be used.