We Catholics genuflect because we are making a sign of reverence before the Real Presence of Our Lord, Body, Blood, Soul and Divinity, in the Tabernacle We make this sign of respect as a way of acknowledging that He is really present there. We are not genuflecting to the altar, but to the Blessed Sacrament.
During the 1980’s and 90’s many Catholic Churches were re-designed and the tabernacle with the Blessed Sacrament was displaced to a side altar, often away from the sanctuary. When one enters such a church, we ought to search for this hidden tabernacle and give Him an acknowledgment of His presence by a reverent genuflection before we enter the pew.
If the monstrance is exposed during Adoration, the custom has been to offer a “double genuflection” that is, to kneel with both knees and bow one’s head. However, new liturgical norms state, “a single genuflection is made in the presence of the Blessed Sacrament, whether reserved in the tabernacle or exposed for public adoration.” The rationale for that change simply is that it is the one Lord who is present in the Holy Eucharist whether in the reserved Sacrament in the tabernacle or in the exposed Sacrament during adoration.
When we enter a Catholic Church for a meeting we often forget that we are in the presence of the Divine. It would be proper to genuflect towards the tabernacle, wherever it is, and kneel in prayer before the speaker/meeting begins.