Religion is bad because it stunts intellectual growth and cripples human interaction; because it is an engine of control and oppression (mostly of women), and because it alienates people from the real, physical world and all its wonders. It narrows horizons, engenders isolation and fear, and strives in most cases to limit and control the experience and value of emotional, sexual and physical pleasure.
To try for quasi-empirical evidence for the "badness" of religion in the GDPs of more or less religious countries, in the level of incarceration, social disruption etc., to say "it leads to poverty!" is to cheapen the argument against religion, to reduce it to a capitalist cost/benefit calculation - and so, perforce, to undermine the secularist, pro-intellectual position.
Secularism is not a substitute for religion or an antonym of it; much like democracy and humanism, it is an independent principle that can stand alone and justify its own moral grounds with internal coherence. A tit-for-tat between so called atheists and deists is not only intellectual masturbation, but debases secularism to level of just another doctrine in a smorgasbord of competing ideologies, when the reality is that there is no equivalence between it and any religious dogma, even the least deist and most tolerant.