but the best internet connection provides less than 10% of the speed of the average LAN
think you are being a bit harsh - I've used linked tables to a sql azure backend with reasonable success - response times are good providing you do the usual things of basing forms on queries that return minimal records, don't use domain functions or UDF's, etc- and of course a decent network connection. Also been able to connect to a web based mySQL database, again with decent performance. Longer term, moving the heavy lifting to the BE also shows benefits. In both cases, performance not as good as terminal server/citrix.
Only rewriting required was some renaming of tables - and of course, relinking.
But don't disagree with your recommendation - if the objective is to enable people to work from home, then terminal server/citrix is an easier way to go. Alternatively consider VPN. One of my clients I support uses an access BE via VPN - every user connects via remote desktop when away from the office and I've found that has the same performance levels. But they have invested in decent resources.
@REZ - you've stated your objective - to enable users to work from home. Moving the BE to sql server is one potential solution but a lot depends on your budget, existing resources, the bandwidth of users home broadband and who is going to support it - not just the maintenance of the BE but the infrastructure the BE runs on.