'Do this or I won't like your build!' blackmailing tactic
While I don't agree with Jo's stance, this is only a blackmailing tactic if Albino cares about having Jo's like. I'd be willing to guess that he doesn't.
As far as constructive goes, Jo is harsh, but he sees the build as lacking originality. That criticism can give Albino something to base future changes on (again, if he cares about Jo's opinion on the matter).
'Do this or I won't like your build!' blackmailing tactic
While I don't agree with Jo's stance, this is only a blackmailing tactic if Albino cares about having Jo's like. I'd be willing to guess that he doesn't.
As far as constructive goes, Jo is harsh, but he sees the build as lacking originality. That criticism can give Albino something to base future changes on (again, if he cares about Jo's opinion on the matter).