Why should we care that there are so many different kinds of bees? In other words, why do we need taxonomists? Bee diversity has been shown to be correlated with flowering plant diversity and can be used as an indicator of how suitable a particular area is for sustaining seed and fruit-bearing plants that are insect-pollinated (without the addition of a managed pollinator like honey bees). If you love your morning cup of coffee, if you love fresh strawberries on your waffles, if you enjoy the comfort of a cotton shirt, if you love apple or cherry pie, if you love cheese and cream from animals that forage on pastureland containing alfalfa, then bee diversity should be very important to you. All of these "other bees", these non-honey-bees, are insurance against the potential loss of honey bees in terms of pollination. Some of these "other bees" are actually better pollinators of particular crops (e.g. blueberries, tomatoes, squash) or help honey bees increase their pollination efficiency (e.g. sunflowers).
When you sip your coffee and eat your fresh fruit, vegetables, nuts and seeds today, think about all of the tiny helpers that brought you these pleasures in life - thank them and the taxonomists for continuing to discover more of them.