whoknows - I've been pondering your situation, because what happened sounds quite upsetting. You've been on my mind all morning!
It's absolutely obvious you're not an undiligent plot holder, but clearly (and reasonably) your gardening is not the only thing in your life either. It strikes me as troubling, verging on discriminatory, that those with other commitments (work, family) aren't given a bit of leeway when it comes to these decisions. What on earth happens to those with physical problems or MH issues or a period of illness - or a period of manic study and work like you've had lately? Allotments should be for people of all ages and walks of life - provided there isn't a really out-of-control weed issue affecting other plots, accepting that some people are going to take slightly longer to bring a full plot into cultivation seems just common sense really.
To be that critical after 10 weeks to your poor neighbour is suggestive of poor judgement, really.
(Sometimes DH has issues with new academics who mark students' work, and they think they are a bit special and have higher standards in their lives than other people because they are extra-harsh with marking and try to fail loads of people. All they are doing in reality is infuriating their senior colleagues, who have to remark all the papers and then give them a telling off for not having the experience to know where a 'normal' undergrad/MA standard is. I wonder if this is the allotment equivalent?!)
Is your site council run? If so, I wonder if you can speak to the council about the approach and suggest that it's maybe a little bit old school??