I think the complaint is more about having bought 4.1 and never using it, rather than paying for an update.
I must admit that I do fall into this category now, I did buy OS4.1 in 2008 and 4.0 before that, but I got a fair few years of use out of them and don't begrudge paying the price. The only reason I stopped using OS4 was down to hardware failure, not a fault of the OS itself.
I still keep an eye on what happens with OS4 though and there are some interesting developments, I will likely buy a copy of FE Classic to try on UAE at least (or if I can find the time and motivation to try and get my A1XE running again).