There have been times in other lotteries, when there has been a couple of rollovers and the prize is huge, where people have tried this.
Maybe not buying all the tickets, but a syndicate buying as many as they can.
As Munkeeluvva says, the problem is the logistics of actually buying the tickets.
First you need to get people to fill out thousands of lottery forms, making sure all the combinations of numbers are covered (not easy in itself).
Then you need loads of people to actually BUY millions of lottery tickets, again not easy to organize.
This may work if you are the only winner, but if the top prize is shared out by many winners you may find it has cost you a lot of money to win very little.