Phil,
Because in the link you supplied there is a how to attach PDF that doesn't make it look like a secure structure on a Celestron. I believe from the Piccys Meade goes right onto the solid back whereas for Celestron
http://starizona.com/acb/Feathertouc...-P984C654.aspx
The insutruction and pdf are quite poorly illustrated and infer the turning moment and weight is on a thin, sub 1mm backplate that is a dust cover for the focuser's internals
http://starizona.com/acb/instruction...%20Focuser.pdf
However I serached further and found here
http://www.starlightinstruments.com/...tructions.html
Which make it abundantly clear this is a solid way to make things work, without placing excessive torque on the backplate!