According to YAHOO finance the last split was in Sept 2003 when the shares were at ~ $140 ($69 post split). Since then the share price has more than doubled. Many folks like to take the tack that splits mean nothing because its just arithmetic and therefore means nothing. If shares were simply priced on arithmetic Tesla would be a penny stock.
Splits do not always generate interest in and of themselves, but a split seems to indicate management has an optimistic outlook and therefore can increase share demand and therefore share price appreciation.