You can either spend a lot of money, then not make the league, and swallow the debt, or not. Lewis doesn't want to do that. It's his choice, since it's his team. He's not beholden to anyone to spend money Spurs don't actually have for our entertainment.
Liverpool are not actually similarly sized to us. They actually make a lot more money than we do. Henry may be worth less than Lewis, but runs his teams for a profit as well. He owns the second richest team in baseball, and they make their money from merchandise and the highest ticket prices outside the Yankees.
If you want the owner to spend more, buy the team and spend more yourself. ENIC are under no obligation to spend anything beyond what Spurs make. They own it, and can run it for a profit if they choose.
As for the report, yes, it's dated, but they haven't released the 2014 report yet. The TV revenue will be up, but for all we know, that money got spent on higher wages. You're making an assertion that there's money available, but providing no actual facts. When asked to, you've complained that the owner isn't willing to take a loss on a business for the sake of your entertainment, and that an unknown amount of revenue can be spent (but we don't actually know if it can), because it should be available. Why should ENIC take a loss on Spurs for you?
You claim "you have to spend money to make money." THFC is choosing to spend their money on building a bigger stadium, with the hope of making more money, to then spend on players. That's their choice, not ours to make.