The DNC and Obama promised wealthy donors presidential access in exchange for bankrolling the convention. Emails released by WikiLeaks shows these request for money were in violation of White House policy. The language of invitations was different for people based on their net worth. Obama clearly was involved in promising his access in exchange for donations.
With the election nearing, it is only natural for the Democrats to reign in Barack Obama to rally the troops and try to get Hilary Clinton in the White House. Besides speeches, endorsements, and appearances, Obama has urged wealthy Democrats to back a convention that will put Clinton over the top of Trump. After a successful RNC, Obama has urged those wealthy backers to put money into the DNC to make it bigger and better than ever. Just like other Democrats, Obama is afraid of what will happen to the liberal values if the Republicans control the White House again.
Both parties have a pretty wide variety of wealthy donors. Money influences politics in the US and until we change that, the two party system will continue to have and to cater to big donors. However, I think with both parties, some standout political leaders are economic draws just by the force of their personalities, or their abilities to get things done. President Obama is a draw. He's been a very strong leader, faced a lot of adversity and continued to handle himself and the country's affairs with grace and class. Why wouldn't a wealthy donor help finance the convention because of him?
The Democratic National Convention has received criticism from all sides. The latest instance of this is allegations that President Obama was involved in convincing wealthy donors to fund the DNC. This is blatantly false; donators are obligated to make their own decisions about funding political events. Therefore Obama had nothing to do with enticing them towards the DNC.