Many Multi-Tablers at your table... +EV or -EV

[12AX7]

I was playing the other day, and some player was cussing folks out. I scanned his handle an found he was playing 3 tables.

So I started checking around, fully 50%-60% of the players on my table were multi-tabling.

Are all these players presumed to be pros or winning players?

So does this indicate I'm playing in a shark tank?