No he isn't, that is the libertarian position. Libertarians like John Stossell and Noam Chomsky can agree on that basic libertarian principle.
Homosexuals: 1.3 Personal Relationships
"Sexual orientation, preference, gender, or gender identity should have no impact on the rights of individuals by government, such as in current marriage, child custody, adoption, immigration or military service laws. Consenting adults should be free to choose their own sexual practices and personal relationships. Government does not have the authority to define, license or restrict personal relationships."
You're also neglecting another libertarian position: that individuals (and by extension, businesses) should be free to associate as they wish.
Don't want queers using your facility for activities ? Fine, don't rent to them. Where it gets sticky on DADT, is that government cannot be allowed to discriminate. But a set of rules that would prevent homosexual activism and favoritism could be put in place that would amount to DADT yet be immune from "discrimination" charges.