And of course I'm ignoring the fact that he actually averaged well over 40 for most of his career....
What does that have to do with anything, though? You can't just look at an average, let alone from a selective period, and form your entire judgement based on that. Glenn McGrath averaged higher than Matthew Hayden in the 2005 Ashes, does that mean he batted better in that series?
Imran was a very useful batsman but he's massively flattered by the "extended period averaging 50+" argument. Certainly he improved greatly with the bat towards the end of his career (when he hardly bowled at all, mind you), but for most of his career he was merely a handy lower order batsman, certainly not someone who was particularly threatening. He's someone who would consistently chip in with runs but rarely turn a game with the bat, in stark contrast to someone like Botham, who was clearly a far better batsman, but less consistent.
Swervy made the point earlier, but to summarise Imran made six test centuries, half against India, one against a "good attack" (against the Windies in 1980), and one in a match that wasn't a draw. If that record belonged to anyone who wasn't also a world class bowler (or a wicket keeper, which is why I mentioned Boucher earlier in the thread) it would be considered extremely poor.
Anyway, I agree with Slifer earlier in the thread, give or take some variation between different eras, a good batsman should average in excess of 40. Aside form the two vastly overrated stalwarts of 90s England in Hussein and Atherton, how many "good" test batsman in history average under 40? You could pick out a few here or there who had lengthy careers, but I don't really think anyone who is genuinely successful with the bat at test level averages under 40. Similar to the 30 mark for a seamer, and something around 33-34 for a spinner, once again give or take some variation based on the era in which the player was around. Obviously you'd expect a quality seamer in the 90s to average under 29, and a batsman who averaged 40 in the 2000-2005 period probably wouldn't be all that special and might even end up getting dropped, but they're decent benchmarks most of the time.
All of this isn't to say that Imran wasn't one of the best all-rounders of all time, because he was. Combining that level of consistently high class bowling with disciplined and useful batting for such a long period is amazing, and the fact that he improved his batting as his bowling declined is a sign of his class as a cricketer, while someone like Botham just went to **** in both areas. However, there's no logic whatsoever to criticising Sobers for his bowling but not Imran for his batting, for neither were what you'd expect from a specialist, but IMO Sobers' bowling was definitely better, and by a distance at that.