I think the decision was probably correct, at least for the full magazine. ePub still seems to be in a state of flux, with every reader client having its little foibles so you can never really stabilise the display layout even on a given screen size, never mind across the full range of sizes or coping with things like monochrome e-paper.
Some folks who publish to mobile devices resort to a special Mobile edition - ouch!
Some, such as Wikipedia, provide a Mobile stylesheet which gives a very different reading experience. Wikipedia can do that because its page format is pretty stable, but for a paper-based magazine layout it would severely constrict creativity.
And anybody with a big enough screen to read the magazine page format already has access to the PDF.
I'd think that for ePub to be worthwhile, LXF would need to develop a Mobile format and automatically single-source both formats, harmonising the paper and mobile content in such a way that each delivers the best experience for the format. Maybe a mix of layout rules, object types and stylesheets. Would be a nice little project for somebody.
"Klinger, do you know how many zoots were killed to make that one suit?" — BJ Hunnicutt, 4077 M*A*S*H