Even at 40% chance of winning against 5 players it's a profitable move. You may lose half the time or more. For example: Let's say the pot is $1000 from 5 players playing (or at least, your share of the pot as some stacks are bigger than yours). At 40% chance of winning, the average result in the long term will be a $400 profit (40% of $1000) which is a double up. Actually, considering you're getting more "bad money" in from their perspective, this move is "per investment" actually more profitable per investment than a single opponent with JTs (82% of $400 = +$128 EV).

In short, this was a poor move, and if you don't have the balls to put your money in when you're ahead I don't think you're on the right track. Godspeed.