He has a point though. I think if they said "you have to buy the next version to get the bug fixes", customers would be quite upset. Some companies do that, but really, these days I would expect to get bug fixes for free.
I think bugfixes clearly have value, but it's a little unclear where exactly they are monetized. Consider: under what circumstances would existing bugs stop you from buying the present version?
- a 100% compatible and 100% feature-comparable alternative product... which additionally has fewer bugs.
- if you know about the bug before buying it. Perhaps this is the crucial factor: you only discover the specific bugs that are a problem for you some time after purchasing it, so they are not well-placed to be purchase-factor.