This varies based on a number of factors. In many places, straddling is legal, but the straddle is not live - that is, the straddler does not buy position. In such a situation, a straddle is obviously a negative-EV move, since the straddler is giving up their opportunity to look at their cards before acting, in return for nothing.
In some cases, the straddle is live. Whether or not it's a good move in this case would depend on a number of factors, and I haven't done an analysis, but I'd hesitantly say that the answer is "sometimes". I've seen straddles used very successfully to steal blinds; the straddler will straddle on their turn, then make a re-raise when it comes around to them, often forcing out anyone who did limp in after the straddle. However, per Wikipedia:
Straddling is considered poor long-term strategy by most experts,
since the benefit of obtaining last action is more than offset by the
cost of making a blind raise. Because straddling has a tendency to
enrich the average pot size without a corresponding increase in the
blinds (and antes if applicable), players who sit at tables that allow
straddling can increase their profits considerably simply by choosing
not to straddle themselves.
A third case is the "button straddle", which I've seen allowed in most Vegas casinos. The player on the button may straddle for a fixed amount, two or three times the big blind; if they do, action starts on the small blind. Again, I haven't evaluated this systematically, but this seems like an obvious win to me: the player on the button gets to effectively raise the stakes only for the hand where he's in the best position to take advantage of it, and buys himself the best position before the flop as well as afterwards.