Yes, PLA is somewhat weaker, but still more than strong enough for most desktop printing applications. It's also much less toxic to print with than ABS.
"Primary gas-phase products of ABS thermal decomposition at very high temperatures have been shown to include carbon monoxide and hydrogen cyanide, as well as a variety of volatile organics (Rutkowski and Levin, 1986). Exposure to thermal decomposition products from ABS has also been shown to have toxic effects in both rats (Zitting and Savolainen, 1980) and mice (Schaper et al., 1994)."
from http://ac.els-cdn.com/S1352231013005086/1-s2.0-S135223101300...