I think that's an unfair assessment. They had a QB who threw 30 interceptions and still went 7-9 which would not be possible without a very good supporting cast. They had one of the best run defences in history, which they've re-signed, and their pass defence was only bad because Winston turned the ball over so much that they faced more passing attempts than anyone else by a mile.
They've got arguably the best pair of WRs in the NFL for Brady to throw to, and supposedly every free agent or player looking for a trade is now interested in getting to Tampa to play with Brady so they might even pick up a few more big name players, they've got about 15m in cap space still. There's also no income tax in Florida which gives them a massive financial advantage.
Brady is also the biggest name in football, maybe the only worldwide household name, so signing him will undoubtedly bring in a ton of revenue from corporate and sponsorships.
With the superbowl coming up in Tampa and the new expanded playoffs I think it's a good move. No one really knows what Brady is going to be like outside of NE but he doesn't have to be much better than one of the most calamitous QBs in history to get them into the playoffs.
It's a well worked out plan, even if it is quite short term, that's what the NFL is about these days. I doubt any Glazer had anything to do with it.