Illegal immigrants, whether they need to learn English or not, present the greatest problem in regards to siphoning taxpayer resources away from American citizens who need help. Illegal immigrants who buck the system and get paid less than minimum wage for doing dirty jobs take this employment away from hard-working Americans who are out of work. Let's solve that dilemma before worrying about whether or not someone needs to learn English.
Anyone who has traveled around the United States of America and has spoken with locals in any region has come to realize that there is more than just accents that differ from place to place, state to state, and region to region. All to often, we become comfortable with the way that we speak, not even considering the option of bettering our language skills personally. The result has been a decline in proper grammar, pronunciation, and a limited vocabulary. While it is important to teach those who enter this nation how to speak our language, it behooves us to ;pay more attention to the needs we ourselves have in needing to hone our English Language skills.
I do not think that people that are trying to learn English are siphoning resources from the USA that can be put to better use to teach other Americans a higher-quality of English. I think that such programs are important to teach those who wish to contribute to the country.
No, English language learners do not siphon resources from the USA that could be put to better use teaching native-born Americans better English, because there are really very few resources diverted to English-language learners. On the other hand, there are problems with native born speakers who have no motivation to learn.