In their estimation, yes. In yours or mine? No. But they are considered a mainline evangelical Christian Church in this country. They're the largest (at least until they began vomiting members and congregations) Lutheran denomination in the US. Then you have the Episcopalians...
But your question was to why wouldn't they be open to homosexuals. You took the narrow view of that openness. They take the broad (secular) view.
I take a narrow view of Christianity, too. And of the defintion of an evangelical church. As a mainline church, the ECLA does not meet the criteria that I believe are the correct ones.