Though I disagree with Mr. Lhota's comments, I'll accept them for the sake of argument.
When gas prices go up, food prices go up. People cut back on "going to the mall" in order to "go to the supermarket." When gas prices go up, people have less purchasing power. When people have less purchasing power, the city doesn't receive as much tax revenue. When the city doesn't have enough tax revenue, they cut services, such as COTA funds.
Wouldn't it be advisable to COTA to invest significantly in light rail, streetcars, etc. NOW while the revenue is there, rather than later, as Mr. Lhota says, when fuel prices are even higher (and the economy slows down even more).
Is it really so difficult to understand the chain links of:
gas prices->people's expendable income->tax revenue->COTA's bankroll to invest in more appropriate transportation ?