I can’t say you are wrong. But can we look at it from another way?
Mr. Tsang tried to encourage HK couples to have more children but yet we found that most of the middle class young couples opt for DINK (double income and no kids) lifestyles for various reasons and therefore the birth rate dropped continuously throughout the last 10 years. The influx of new PRC babies can help to alleviate the population problems. Although the overall education, medical expenses budget may be increased, if the babies received proper education and work in HK, they can create values and pay tax as well. I was grown up under the 9 yrs free education plan and now I work and pay tax to support the HK economy. My parents came to HK without a penny in early 50’s, I think the new comers should be better now. The only difference is the proportion of middle class who complaint about the poor one at that time was much smaller than now.