weight-wise sugar has only half of fructose, and fructose is main offender. So yes, too much sugar is bad, but if you compare gram to gram, fructose is worse.
Most commonly used HFCS varieties contains 42% or 55% fructose [1], which compares well with 50% in sucrose.
[1] https://en.wikipedia.org/wiki/High_fructose_corn_syrup#Compo...