When it comes to humans and wildlife, feeding wildlife only becomes a problem when the wildlife start to infiltrate human property and can harm humans. Feeding birds is considered fun because you draw them near and they are pleasant to see. Bear feeders would be a problem, but hummingbird feeders in National Parks are still common. I think Elk and deer that cause wrecks on highways are a problem. Think about the infestations of whitetail dear in the east, and the Elk on the highways up here. The deer numbers are high, and a lack of predators is part of the issue (though the automobile has replaced the carnivore), but the real issue is habitat improvements like endless suburban lawns and the creation of enormous areas of edge habitat which is perfect for whitetails. In our area, tanks which were created in the last 100 years or so for cattle benefit Elk and Mule dear. Before that time there was almost no surface water over much of the forested highlands of the western Mogollon Rim. A driver like myself, and an ecologist concerned about the health of the ecosystem in the area would see artificially high Elk numbers to be problematic, but I doubt hunters would ever see that as a problem unless disease infiltrates the population.
Feeding a bird is no cause for concern for 99% of people. It will undoubtedly raise the population of certain species. Most would see that as an inconsequential affect on overall avian richness. If for some reason, the birds that benefit from the feeding started to out compete other natives and a species began to decline, then it would start to be a problem. There would still be people who feed birds, and near human habitat that negatively impacted species would be affected. We aren't everywhere up here, and the effects of bird feeding probably are not, nor could they ever be as problematic as humans feeding bears and the bears then tearing open cars and houses to get to food they smell.
Pigeons aren't usually fed, and I never see a pigeon feeder. They seem to feed off of trash, so they are more like a flying rat. Gulls can be a problem, but they are attracted to the trash people leave out. Gull are notorious around landfills in coastal areas. The Canada Goose is a serious pest on golf courses, but it would be easy to contain if we just started killing them with out mercy, or eliminated lush green grass which they feed on. Either or.
I think Monsoon season will begin around June 20, plus or minus 5 days, not by the calendar according to the NWS, but when dew points rise dramatically, and it begins to rain over the Sacramento Mountains. It will start about 10 days later in Arizona.