I just read C.S. Lewis's An Experiment in Criticism, and I thought it would be fun to adapt it to typography:
Good fonts are those which permit, invite, or compel good design. The function of typographic criticism is to multiply, prolong, and safeguard experiences of good design.
If I say I like Helvetica, and you are sure that it is bad, then you could say my taste is bad. On what do you base your position? If it is your own taste, then you are just being insolent. If you say so because of the prevailing view of the typographic community, then how long will this last? It is only a matter of time before fashion changes.