Sports venues have to trade off the wishes of one set of fans who want to express themselves against the rest who have to see their shirts, signs, etc. If they don't draw a line somewhere, you know the messages will degenerate further. The Yankees, and apparently the Rangers, have decided to draw the line at "Sucks". I agree with their decisions. Wish our shopping malls would do the same.
I did find the use of "Sucks" funny once on TV. There was a drippy show called the Silver Spoons. John Houseman was a guest star and people were assuming he liked some painting. In his best, stuffy British voice he rebuked them saying: "I think it sucks." The shock value (him, back then) was funny.
“That team sure did suck last night. They just plain sucked! I’ve seen teams suck before, but they were the suckiest bunch of sucks that ever sucked!”