Speed control using the throttle/ thrust lever is just as important in maintaining your flying skills.
I wouldn't disagree but we are stuck with the SOPs.
On the rare occasions anyone in the "head shed" has tried to justify the policy the logic rolled out is that the safety benefits of using auto throttle (e.g. low speed protection, reduced landing dispersion) out weigh the increased risk...
Regardless of whether an autopilot out/autothrottle in approach can be called hand flown or not I would agree it is deskilling...I personally don't like the policy, I think autothrottle/auto thrust should be optional but as I said on the line we are stuck with it so please don't shoot the messenger....