The Glazers bought the club in a hostile takeover, it was not actually for sale. Then of course there is the debt which is still an issue today.
The club and the fans tried to stop them, but there was a boardroom rift with major shareholders and as a publicly listed company anyone could buy the shares.
Many fans were shareholders (including me) and did not want to sell, we were happy with the PLC but had no choice due to takeover rules.
Some fans did boycott and give up ST tickets, some even formed a new club. There was a big split in the matchgoing fanbase that has taken many years to heal.
Read here:
http://news.bbc.co.uk/1/hi/business/4540939.stm
Compare that to today, where the club is openly for sale and most fans desperate for a new owner after a decade of poor performance.
Absolutely bizarre to me that a potential owner shows up who wants to get rid of the Glazers, clear the debt and promise to invest in the stadium but some fans, who happily supported during the Glazers years, think this is the time to stop supporting the club?!
Honestly I don't get it at all