Football can be played/practiced on any large grass field in any climate any time of the year. Hockey requires an indoor facility with expensive chilling and maintenance equipment if you want to play outside of a few northern cities for a few months out of the year. Inner city Houston kids will never have access to hockey facilities in any significant numbers.

Do inner city schools play basketball outside? Although, I can see maintaining a hockey rink has increased costs over a basketball court.

The expenses are high and the exceptional players start very young.